CN115327689A

CN115327689A - Optically anisotropic film and laminate comprising same

Info

Publication number: CN115327689A
Application number: CN202210503602.3A
Authority: CN
Inventors: 森本贤介; 幡中伸行; 名田敬之
Original assignee: Sumitomo Chemical Co Ltd
Current assignee: Sumitomo Chemical Co Ltd
Priority date: 2021-05-11
Filing date: 2022-05-09
Publication date: 2022-11-11
Also published as: TW202248313A; KR20220153507A; JP2022174723A; US20220384739A1

Abstract

Provided are an optically anisotropic film which can more effectively reduce the difference in color between a front color tone and an oblique color tone when an organic EL display device displays white, and can exhibit good image display characteristics, and a laminate comprising the optically anisotropic film. The optically anisotropic film is a cured film of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound and at least 2 kinds of dichroic dyes, and is a film obtained by curing the polymerizable liquid crystal compound and at least 2 kinds of dichroic dyes in a state of being molecularly oriented in a perpendicular direction with respect to a film plane, and satisfies a specific relationship.

Description

Optically anisotropic film and laminate comprising same

Technical Field

The present invention relates to an optically anisotropic film, a laminate comprising the optically anisotropic film, and an organic EL display device comprising the laminate.

Background

In general, in a widely used organic EL display device, a color tone when viewed from the front side is different from a color tone when viewed from an oblique direction in white display, and there is a problem that a color and a taste change depending on an angle at which an image is viewed. In view of the above, it has been found that the use of a laminate comprising a vertically aligned liquid crystal cured film which is a cured product of a polymerizable liquid crystal composition comprising a polymerizable liquid crystal compound and a dichroic dye having a single maximum absorption wavelength and a horizontally aligned retardation film has an effect of reducing the viewing angle dependence (for example, patent document 1).

Documents of the prior art

Patent literature

Patent document 1: japanese patent laid-open No. 2020-076920

Disclosure of Invention

Problems to be solved by the invention

However, there is a strong demand for improvement of the oblique color tone at the time of white display of an organic EL display device, and further improvement of the effect of reducing the viewing angle dependency at the time of white display, which can be improved even by slight coloring of the oblique color tone, is desired.

Accordingly, an object of the present invention is to provide an optically anisotropic film that can more effectively reduce the difference in color between a front color tone and an oblique color tone in white display of an organic EL display device and can exhibit good image display characteristics, and a laminate including the optically anisotropic film.

Means for solving the problems

The present inventors have conducted extensive studies to solve the above problems, and as a result, the present invention has been completed. That is, the present invention includes the following aspects.

[1] An optically anisotropic film which is a cured film of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound and at least 2 kinds of dichroic dyes, is obtained by curing the polymerizable liquid crystal compound and at least 2 kinds of dichroic dyes in a state of being molecularly oriented in a perpendicular direction with respect to a film plane, and satisfies the following formulae (1) to (6) or formulae (4) to (9):

0.001≤Ax450(z＝50)≤0.100 (1)

0.070≤Ax550(z＝50)≤1.000 (2)

0.070≤Ax650(z＝50)≤1.000 (3)

0.001≤Ax450≤0.050 (4)

0.001≤Ax550≤0.050 (5)

0.001≤Ax650≤0.050 (6)

0.050≤Ax450(z＝50)≤1.000 (7)

0.070≤Ax550(z＝50)≤1.000 (8)

0.001≤Ax650(z＝50)≤0.100 (9)

in expressions (1) to (9), ax λ and Ax λ (z = 50) are both absorbance at a wavelength λ nm, ax represents absorbance of linearly polarized light oscillating in the x-axis direction, ax (z = 50) represents absorbance of linearly polarized light oscillating in the x-axis direction when the optically anisotropic film is rotated by 50 ° about the y-axis as a rotation axis, where the x-axis represents an arbitrary direction in the film surface of the optically anisotropic film, the y-axis represents a direction orthogonal to the x-axis in the film surface, and the z-axis represents a thickness direction of the optically anisotropic film.

[2] The optically anisotropic film according to [1], wherein the at least 2 kinds of dichroic dyes include a combination of at least 1 kind of cyan dye and at least 1 kind of magenta dye, or a combination of at least 1 kind of yellow dye and at least 1 kind of magenta dye.

[3] The optically anisotropic film according to [1] or [2], which satisfies any one of the following formulae (10) and (11):

0.1≤Ax450(z＝50)/Ax550(z＝50)≤1.5 (10)

0.1≤Ax650(z＝50)/Ax550(z＝50)≤1.5 (11)

in formulas (10) and (11), ax λ and Ax λ (z = 50) have the same meaning as described above.

[4] The optically anisotropic film according to any one of the above [1] to [3], having a film thickness of 0.1 μm or more and 5 μm or less,

the optically anisotropic film contains the at least 2 kinds of dichroic dyes in an amount of 0.1 parts by mass or more and 5 parts by mass or less, respectively, with respect to 100 parts by mass of the polymerizable liquid crystal compound.

[5] The optically anisotropic film according to [4], wherein the at least 2 dichroic dyes comprise a combination of at least 1 cyan dye and at least 1 magenta dye, or a combination of at least 1 yellow dye and at least 1 magenta dye,

the optically anisotropic film satisfies the following formula (12) and formula (13):

T×D1＝0.4～1.7 (12)

T×D2＝0.6～2.7 (13)

in formulas (12) and (13), T represents a film thickness (μm), D1 represents an amount (parts by mass) of a cyan dye or a yellow dye with respect to 100 parts by mass of a polymerizable liquid crystal compound, and D2 represents an amount (parts by mass) of a magenta dye with respect to 100 parts by mass of a polymerizable liquid crystal compound.

[6] The optically anisotropic film according to any one of the above [1] to [5], wherein at least 1 azo dye is contained as the dichroic dye.

[7] The optically anisotropic film according to any one of the above [1] to [6], wherein the polymerizable liquid crystal compound is a liquid crystal compound exhibiting a higher order smectic liquid crystal phase.

[8] A laminate comprising the optically anisotropic film, polarizing film and horizontally oriented retardation film according to any one of [1] to [7 ].

[9] The laminate according to [8], which comprises an optically anisotropic film, a polarizing film and a horizontally oriented retardation film in this order.

[10] The laminate according to item [9], further comprising a vertically aligned phase difference film on a side of the horizontally aligned phase difference film opposite to the polarizing film.

[11] An organic EL display device comprising the laminate according to any one of [8] to [10 ].

Effects of the invention

According to the present invention, it is possible to provide an optically anisotropic film which can more effectively reduce the difference in color tone between the front color tone and the oblique color tone at the time of white display of an organic EL display device and can exhibit favorable image display characteristics, and a laminate comprising the optically anisotropic film.

Detailed Description

< optically anisotropic film >

The optically anisotropic film of the present invention is a cured film of a polymerizable liquid crystal composition (hereinafter, also referred to as "composition for forming an optically anisotropic film") containing a polymerizable liquid crystal compound and at least 2 kinds of dichroic dyes. The cured film is obtained by curing the polymerizable liquid crystal compound and the at least 2 kinds of dichroic dyes in a state of being molecularly oriented in a direction perpendicular to a film plane of the liquid crystal cured film, and satisfies the following formulas (1) to (6) or formulas (4) to (9).

0.001≤Ax450(z＝50)≤0.100 (1)

0.070≤Ax550(z＝50)≤1.000 (2)

0.070≤Ax650(z＝50)≤1.000 (3)

0.001≤Ax450≤0.050 (4)

0.001≤Ax550≤0.050 (5)

0.001≤Ax650≤0.050 (6)

0.050≤Ax450(z＝50)≤1.000 (7)

0.070≤Ax550(z＝50)≤1.000 (8)

0.001≤Ax650(z＝50)≤0.100 (9)

In the formulae (1) to (9), ax λ and Ax λ (z = 50) are both absorbances at a wavelength λ nm. Ax represents the absorbance of linearly polarized light oscillating in the x-axis direction, and Ax λ (z = 50) represents the absorbance of linearly polarized light oscillating in the x-axis direction when the optically anisotropic film is rotated by 50 ° about the y-axis as the rotation axis. Here, the x-axis refers to an arbitrary direction within the film surface of the optically anisotropic film, the y-axis refers to a direction orthogonal to the x-axis within the film surface, and the z-axis refers to the thickness direction of the optically anisotropic film.

The absorbance in the present specification means absorbance when measurement is performed in a state where the influence of the interface reflection at all the times of measurement is eliminated. As a method for eliminating the influence of the interface reflection, for example, a method of measuring absorbance at a wavelength where absorption of a compound is negligible at a long wavelength such as 800nm using a spectrophotometer with the absorbance at the wavelength being 0 in a region where the absorption of the compound is present is exemplified.

The Ax λ can be measured by allowing the same linearly polarized light as that for measuring the Ax to enter in a state where the optically anisotropic film is rotated by 50 ° about the y-axis as a rotation axis (z = 50). Here, the film in which Ax was measured was rotated by 50 ° in the incident direction of linearly polarized light with the y-axis as the rotation axis. It can be said that the smaller the value of Ax λ (z = 50), the smaller the absorption of light near the wavelength λ nm in the oblique direction by the optically anisotropic film, and the larger the value of Ax λ (z = 50), the larger the absorption of light near the wavelength λ nm in the oblique direction by the optically anisotropic film. By controlling the value of Ax λ (z = 50) at 450nm, 550nm, and 650nm, light of a specific wavelength can be selectively absorbed in the oblique direction of the optically anisotropic film, and the oblique color tone at the time of white display when incorporated in an organic EL display device can be improved.

In the following description, the effect of improving (changing) the "oblique color tone" in the present specification refers to an effect of improving the oblique color tone in white display (that is, an effect of reducing coloring in a case of viewing from an oblique direction in white display) when the optical anisotropic film and the horizontally oriented retardation film are combined and applied to a display device. When the effect of improving the oblique hue in white display is high, the difference in hue between the front hue and the oblique hue in white display tends to be small, and therefore, this is preferable.

The Ax λ can be measured by applying linearly polarized light oscillating in the x-axis direction to the film surface of the optically anisotropic film from the z-axis direction. It can be said that the smaller the value of Ax λ, the smaller the absorption of light near the wavelength λ nm in the front direction by the optically anisotropic film, the better the transmittance for light from the front direction, and the better the front color tone at the time of white display when incorporated in an organic EL display device.

In the following description, the effect of improving (changing) the "front color tone" in the present specification refers to an effect of improving the front color tone in white display (that is, an effect of reducing coloring in the case of viewing from the front direction in white display) when the optical anisotropic film and the horizontally oriented retardation film are combined and applied to a display device. The absorbance of linearly polarized light that oscillates in the y-axis direction from the z-axis direction toward the film surface of the optically anisotropic film is represented by Ay λ, and in the optically anisotropic film of the present invention, ax λ and Ay λ are generally substantially equal to each other. When Ax λ and Ay λ are different from each other, dichroism occurs in a plane, and in this case, the coloring of the optically anisotropic film in a front color tone tends to be large.

By satisfying the above equations (1) to (6) or the above equations (4) to (9), an optically anisotropic film can be obtained that can efficiently transmit light in the front direction of the optically anisotropic film and can selectively absorb light of a specific wavelength in an oblique direction. It can be said that the optically anisotropic film having such optical characteristics has excellent polarization performance (light absorption anisotropy ability), and can reduce the difference in color tone between the front color tone and the oblique color tone at the time of white display when incorporated in an organic EL display device.

In one embodiment of the present invention, the optically anisotropic film of the present invention satisfies the above-described formulas (1) to (6) (hereinafter, the optically anisotropic film satisfying the formulas (1) to (6) is also referred to as "optically anisotropic film (a)"). When the optically anisotropic film (a) satisfies the above equations (1) to (3), the film shows substantially no absorption of light having a wavelength of around 450nm in the oblique direction, but absorbs light having wavelengths of around 550nm and around 650 nm. Further, satisfying the formulas (4) to (6) results in substantially no absorption of light having a wavelength of 450nm to 650nm in the front direction.

In another embodiment of the present invention, the optically anisotropic film of the present invention satisfies the above formulas (4) to (9) (hereinafter, the optically anisotropic film satisfying the formulas (4) to (9) is also referred to as "optically anisotropic film (b)"). When the optically anisotropic film (b) satisfies the above equations (7) to (9), it shows substantially no absorption of light having a wavelength of around 650nm in the oblique direction, but absorbs light having wavelengths of around 450nm and around 550 nm. Further, satisfying the formulas (4) to (6) results in substantially no absorption of light having a wavelength of 450nm to 650nm in the front direction.

In the optically anisotropic film of the present invention satisfying the formulas (1) to (6) or the formulas (4) to (9), at least 2 kinds of dichroic dyes are present in the polymerizable liquid crystal compound, and the polymerizable liquid crystal compound and at least 2 kinds of dichroic dyes are aligned with a high degree of order in the vertical direction of the liquid crystal cured film. By having such optical characteristics, the transmittance for light from the front direction is excellent in the white display, and the light having a specific wavelength exhibits high selective absorption in the oblique direction, so that the difference in color tone between the front color tone and the oblique color tone can be further reduced in the white display when incorporated in the organic EL display device. Such an optically anisotropic film of the present invention can eliminate coloring when a display constituting an organic EL display device is viewed from an oblique direction, and thus can effectively suppress a change in color tone in an oblique direction when the organic EL display device is white-displayed. For example, by selecting the optically anisotropic film (a) or the optically anisotropic film (b) having a relationship of complementary colors for the color tone when the organic EL display is white-displayed (when white-emitted) inclined at 45 °, the color tone of the display when the organic EL display device is viewed from an oblique direction can be canceled, and the change in the oblique color tone can be suppressed without affecting the color tone in the front direction when white-displayed.

Displays for organic EL display devices, which have been widely used in the past, are generally yellow-looking displays and blue-looking displays in many cases when viewed from an oblique direction. For example, the oblique color tone at the time of white display can be improved by using the optically anisotropic film (a) which exhibits substantially no absorption of light having a wavelength of around 450nm but absorbs light having wavelengths of around 550nm and around 650nm in combination with a display having maximum light emission between wavelengths of 550nm and 700nm at the time of white display inclined at 45 ° (for example, a display having a yellow color tone in an oblique direction in a typical case). Further, for example, by using the optically anisotropic film (b) which exhibits substantially no absorption of light having a wavelength of around 650nm but absorbs light having wavelengths of around 450nm and around 550nm in combination with a display having a maximum light emission at wavelengths of between 400 and 550nm in white display inclined at 45 ° (for example, a display which emits blue in an oblique color tone in a typical case), it is possible to improve the oblique color tone in white display.

In the optically anisotropic film (a), a value of Ax450 (z = 50) is 0.001 or more and 0.100 or less, and values of Ax550 (z = 50) and Ax650 (z = 50) are 0.070 or more and 1.000 or less, respectively. In the optically anisotropic film (a), the value of Ax450 (z = 50) is preferably 0.005 or more, more preferably 0.010 or more, and further preferably 0.080 or less, and more preferably 0.075 or less, in terms of facilitating selective absorption of light of the specific wavelength in an oblique direction and facilitating improvement of an oblique color tone at the time of white display. The value of Ax550 (z = 50) is preferably 0.080 or more, more preferably 0.100 or more, and is preferably 0.800 or less, more preferably 0.500 or less. The value of Ax650 (z = 50) is preferably 0.080 or more, more preferably 0.100 or more, and is preferably 0.800 or less, more preferably 0.500 or less.

In the optically anisotropic film (b), a value of Ax450 (z = 50) is 0.050 or more and 1.000 or less, a value of Ax550 (z = 50) is 0.070 or more and 1.000 or less, and a value of Ax650 (z = 50) is 0.001 or more and 0.1 or less. In the optically anisotropic film (b), the value of Ax450 (z = 50) is preferably 0.060 or more, more preferably 0.070 or more, further preferably 0.080 or more, particularly preferably 0.100 or more, and further preferably 0.800 or less, and more preferably 0.500 or less, from the viewpoint of facilitating selective absorption of light of the specific wavelength in an oblique direction and facilitating improvement of an oblique color tone at the time of white display. The value of Ax550 (z = 50) is preferably 0.080 or more, more preferably 0.090 or more, further preferably 0.100 or more, and further preferably 0.800 or less, more preferably 0.500 or less. The value of Ax650 (z = 50) is preferably 0.005 or more, more preferably 0.010 or more, and is preferably 0.080 or less, more preferably 0.075 or less.

In the optically anisotropic film (a) and the optically anisotropic film (b), values of Ax450, ax550, and Ax650 are all 0.001 or more and 0.050 or less. From the viewpoint of enhancing the front color tone at the time of white display, the values of Ax450, ax550, and Ax650 are each preferably 0.040 or less, more preferably 0.030 or less, and even more preferably 0.025 or less.

The values of Ax λ and Ax λ (z = 50) of the optically anisotropic film can be controlled by, for example, the type and the amount of the dichroic dye constituting the optically anisotropic film. Further, for example, the thickness of the optically anisotropic film, the conditions of the production process, the type and the amount of the polymerizable liquid crystal compound constituting the optically anisotropic film may be controlled by adjusting the thickness.

The optically anisotropic film of the present invention is constituted containing at least 2 dichroic pigments. The dichroic dye is a dye having a property that the absorbance of a molecule in the major axis direction is different from the absorbance of the molecule in the minor axis direction. The dye having such properties is not limited to the dichroic dye, and may be a dye or a pigment. Two or more dyes may be used in combination, two or more pigments may be used in combination, or a dye and a pigment may be used in combination.

In order for the optically anisotropic layer to satisfy the optical properties represented by the above formulas (1) to (3) or formulas (7) to (9), it is preferable that the at least 2 kinds of dichroic dyes constituting the optically anisotropic film of the present invention include 2 different kinds of dichroic dyes selected from a cyan dye, a magenta dye, and a yellow dye. Here, in the present specification, a cyan dye refers to a dichroic dye having a maximum absorption at a wavelength of 570nm or more and 700nm or less. The magenta pigment is a dichroic pigment having a maximum absorption at a wavelength of 480nm or more and less than 570 nm. The yellow dye is a dichroic dye having a maximum absorption at a wavelength of 380nm or more and less than 480 nm. In the present invention, the phrase "including different 2 kinds of dichroic dyes" means that, for example, a combination of a cyan dye and a magenta dye, or a combination of a magenta dye and a yellow dye includes at least 2 kinds of dichroic dyes selected from different dye groups classified into a cyan dye, a magenta dye, and a yellow dye. Therefore, for example, in the case where only 2 or more kinds of dichroic dyes each belonging to a cyan dye are contained as dichroic dyes constituting the optically anisotropic film, the optically anisotropic film cannot be said to "contain at least 2 kinds of dichroic dyes" in the meaning of the present specification. The absorbance of the dichroic dye may be measured with a spectrophotometer in a state of being dissolved in a solvent such as chloroform in which the dichroic dye is dissolved.

The at least 2 dichroic dyes are preferably a combination of at least 1 cyan dye and at least 1 magenta dye (hereinafter also referred to as "combination (a)"), or a combination of at least 1 yellow dye and at least 1 magenta dye (hereinafter also referred to as "combination (b)"). By including the combination (a) as the dichroic dye, an optically anisotropic film satisfying the above formulas (2) and (3) can be produced. Further, by including the combination (b) as a dichroic dye, an optically anisotropic film satisfying the above formulas (7) and (8) can be produced. When the optically anisotropic film includes the combination (a) as the dichroic dye, it is preferable that the optically anisotropic film does not substantially include the yellow dye in order to impart desired optical characteristics (that is, optical characteristics satisfying the formula (1)) to the optically anisotropic film. The optically anisotropic film can be an optically anisotropic film (a). Similarly, when the optically anisotropic film is configured to include the combination (b) as a dichroic dye, it is preferable that the optically anisotropic film does not substantially include a cyan dye in order to impart desired optical characteristics (that is, optical characteristics satisfying the formula (9)) to the optically anisotropic film. The optically anisotropic film can be an optically anisotropic film (b). Here, "substantially not contained" means that the content of the target dye is 0.25 parts by mass or less, preferably 0.10 parts by mass or less, and the content of the target dye may be 0 parts by mass, based on 100 parts by mass of the polymerizable liquid crystal compound forming the optically anisotropic film. As long as the optically anisotropic film satisfies the formulas (1) to (3) or the formulas (7) to (9), a small amount of yellow pigment may be contained together with the combination (a), or a small amount of cyan pigment may be contained together with the combination (b).

In the present invention, the optically anisotropic film preferably satisfies any one of the following formulas (10) and (11).

0.1≤Ax450(z＝50)/Ax550(z＝50)≤1.5 (10)

0.1≤Ax650(z＝50)/Ax550(z＝50)≤1.5 (11)

In expressions (10) and (11), ax λ (z = 50) has the same meaning as described above. Angle (c)

The formula (10) is such that the ratio of the absorbance at a wavelength of 450nm to the absorbance at a wavelength of 550nm in the oblique direction of the optically anisotropic film is 0.1 to 1.5. The expression (11) indicates that the ratio of the absorbance at a wavelength of 650nm to the absorbance at a wavelength of 550nm in the oblique direction of the optically anisotropic film is 0.1 to 1.5. When the optically anisotropic film satisfies any of the formulae (10) and (11), the selective absorption of light having a specific wavelength in an oblique direction is improved, and the oblique color tone in white display is easily improved. In particular, when the optically anisotropic film is the optically anisotropic film (a), the formula (11) is preferably satisfied, and when the optically anisotropic film is the optically anisotropic film (b), the formula (10) is preferably satisfied. From the viewpoint of more easily improving the oblique color tone in white display, the value of Ax450 (z = 50)/Ax 550 (z = 50) is more preferably 0.2 or more, further preferably 0.3 or more, and further preferably 1.2 or less, further preferably 1.0 or less. Similarly, from the viewpoint of more easily improving the oblique color tone in white display, the value of Ax650 (z = 50)/Ax 550 (z = 50) is more preferably 0.3 or more, still more preferably 0.4 or more, and still more preferably 1.4 or less, still more preferably 1.3 or less.

The value of Ax450 (z = 50)/Ax 550 (z = 50) and the value of Ax650 (z = 50)/Ax 550 (z = 50) can be controlled by adjusting the kind and the amount of the dichroic dye constituting the optically anisotropic film. Specifically, an optically anisotropic film satisfying formula (10) can be obtained by using a yellow pigment and a magenta pigment as dichroic pigments and adjusting the blending ratio thereof. Further, by using a cyan dye and a magenta dye as dichroic dyes and adjusting the blending ratio thereof, an optically anisotropic film satisfying formula (11) can be obtained.

In the present invention, the content of the at least 2 kinds of dichroic dyes may be appropriately determined according to the desired optical characteristics of the optically anisotropic film and the kind of display constituting the display device incorporating the optically anisotropic film. In one embodiment of the present invention, when the film thickness of the optically anisotropic film of the present invention is 0.1 μm or more and 5 μm or less, the film is preferably formed from a polymerizable liquid crystal composition containing the at least 2 kinds of dichroic dyes in an amount of 0.1 parts by mass or more and 5 parts by mass or less, respectively, with respect to 100 parts by mass of the polymerizable liquid crystal compound. When the content of the dichroic dye is within the above range, the absorbance of the optically anisotropic film can be easily controlled to a desired range, and an optically anisotropic film having excellent color tone in an oblique direction in white display can be obtained. In the optically anisotropic film of the present invention, the content of the dichroic dye is more preferably 0.3 parts by mass or more, further preferably 0.5 parts by mass or more, and further more preferably 4.5 parts by mass or less, further preferably 4 parts by mass or less, per 100 parts by mass of the polymerizable liquid crystal compound. In the case where the dichroic dye of the same kind classified into a cyan dye, a magenta dye, or a yellow dye is contained in 2 or more kinds (that is, for example, in the case where the dichroic dye contains a plurality of kinds classified into cyan dyes), the total content of the dichroic dyes of the same kind is preferably within the above range.

When the optically anisotropic film is the optically anisotropic film (a), the film thickness is preferably 0.1 to 5 μm, and the magenta pigment and the cyan pigment are contained in an amount of 0.1 to 5 parts by mass, respectively, based on 100 parts by mass of the polymerizable liquid crystal compound. In the optically anisotropic film (a) having the above film thickness, the content of the cyan dye (the total content thereof when 2 or more species are contained) is preferably 0.3 parts by mass or more, more preferably 0.5 parts by mass or more, and further preferably 4.5 parts by mass or less, more preferably 4 parts by mass or less. In the optically anisotropic film (a) having the above film thickness, the content of the magenta pigment (the total content thereof in the case where 2 or more species are contained) is preferably 0.3 parts by mass or more, more preferably 0.5 parts by mass or more, and is preferably 4.5 parts by mass or less, more preferably 4 parts by mass or less.

When the optically anisotropic film is the optically anisotropic film (b), the film thickness is preferably 0.1 to 5 μm, and the magenta pigment and the yellow pigment are contained in an amount of 0.1 to 5 parts by mass, respectively, based on 100 parts by mass of the polymerizable liquid crystal compound. In the optically anisotropic film (b) having the above film thickness, the content of the yellow coloring matter (the total content thereof in the case where 2 or more species are contained) is preferably 0.3 parts by mass or more, more preferably 0.5 parts by mass or more, and further preferably 4.5 parts by mass or less, more preferably 4 parts by mass or less. In the optically anisotropic film (b) having the above film thickness, the content of the magenta pigment (the total content thereof in the case where 2 or more types are included) is preferably 0.3 parts by mass or more, more preferably 0.5 parts by mass or more, and is preferably 4.5 parts by mass or less, more preferably 4 parts by mass or less.

In the case where the displays constituting the display device are the same, the absorbance of the optically anisotropic film necessary for improving the color tone in the oblique direction in the white display of the display device incorporating the display device is the same (constant). Therefore, the content of the dichroic dye in the optically anisotropic film of the present invention can be defined based on the amount of the polymerizable liquid crystal compound constituting the optically anisotropic film in relation to the film thickness of the optically anisotropic film.

In the present invention, when the at least 2 kinds of dichroic dyes include a combination of at least 1 kind of cyan dye and at least 1 kind of magenta dye, or a combination of at least 1 kind of yellow dye and at least 1 kind of magenta dye,

preferably, the following formulas (12) and (13) are satisfied:

T×D1＝0.4～1.7 (12)

T×D2＝0.6～2.7 (13)

in the formulae (12) and (13), T represents the film thickness (μm), D1 represents the amount (parts by mass) of the cyan dye or the yellow dye with respect to 100 parts by mass of the polymerizable liquid crystal compound, and D2 represents the amount (parts by mass) of the magenta dye with respect to 100 parts by mass of the polymerizable liquid crystal compound. When the optically anisotropic film satisfies the above formulae (12) and (13), the absorbance of the optically anisotropic film can be easily controlled to a desired range, and an optically anisotropic film having excellent color tone in an oblique direction in white display can be easily obtained. From the viewpoint of more easily improving the diagonal color tone in white display, the value of T × D1 is more preferably 0.5 or more, still more preferably 0.7 or more, and still more preferably 1.6 or less, still more preferably 1.3 or less. Similarly, the value of T × D2 is more preferably 0.8 or more, further preferably 1.0 or more, and further preferably 2.5 or less, further preferably 2.2 or less.

In the present invention, the dichroic dye is not particularly limited as long as it is a dichroic dye capable of forming an optically anisotropic film satisfying the above-described formulas (1) to (3) or (7) to (9), and any known dichroic dye in the field of optical films can be used. Examples of such dichroic dyes include acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes, and anthraquinone dyes. Among them, azo pigments are preferred. Examples of the azo dye include monoazo dye, disazo dye, trisazo dye, tetraazo dye, and stilbene azo dye, and disazo dye and trisazo dye are preferable.

Examples of the azo dye include a compound represented by the formula (I) (hereinafter also referred to as "compound (I)").

K ¹ (-N＝N-K ² ) _p -N＝N-K ³ (I)

[ in the formula (I), K ¹ And K ³ Independently represent an optionally substituted phenyl group, an optionally substituted naphthyl group, an optionally substituted phenylbenzoate group or an optionally substituted 1-valent heterocyclic group. K is ² Represents a p-phenylene group which may have a substituent, a naphthalene-1, 4-diyl group which may have a substituent, a4, 4' -stilbenylene group which may have a substituent or a 2-valent heterocyclic group which may have a substituent. p represents an integer of 0 to 4. When p is an integer of 2 or more, a plurality of K ² May be the same or different from each other. the-N = N-bond may be replaced by-C = C-, -COO-, -NHCO-, -N = CH-bond in a range showing absorption in the visible region.]

Examples of the heterocyclic group having a valence of 1 include groups obtained by removing 1 hydrogen atom from a heterocyclic compound such as quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzimidazole, oxazole and benzoxazole. Examples of the 2-valent heterocyclic group include those obtained by removing 2 hydrogen atoms from the above-mentioned heterocyclic compounds.

As K ¹ And K ³ In (1) phenyl, naphthyl, benzoate and heterocyclic group having a valence of 1, and K ² The substituent optionally contained in the p-phenylene group, naphthalene-1, 4-diyl group, 4' -stilbenylene group and 2-valent heterocyclic group in (a) includes an alkyl group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms and having a polymerizable group, and an alkenyl group having 1 to 4 carbon atoms; methoxy group, ethyl groupAlkoxy groups having 1 to 20 carbon atoms such as oxy group and butoxy group; an alkoxy group having 1 to 20 carbon atoms and having a polymerizable group; a fluoroalkyl group having 1 to 4 carbon atoms such as a trifluoromethyl group; a cyano group; a nitro group; a halogen atom; a substituted or unsubstituted amino group such as an amino group, a diethylamino group, or a pyrrolidinyl group (the substituted amino group means an amino group having 1 or 2 alkyl groups having 1 to 6 carbon atoms, an amino group having 1 or 2 alkyl groups having 1 to 6 carbon atoms and a polymerizable group, or an amino group in which 2 substituted alkyl groups are bonded to each other to form an alkanediyl group having 2 to 8 carbon atoms, and the unsubstituted amino group is-NH ₂ . ) And so on. Examples of the polymerizable group include a (meth) acryloyl group, a (meth) acryloyloxy group, and the like.

Among the compounds (I), the compounds represented by any of the following formulae (I-1) to (I-8) are also preferable.

[ solution 1]

[ formulae (I-1) to (I-8),

B ¹ ～B ³⁰ independently of each other, a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, a nitro group, a substituted or unsubstituted amino group (the definitions of the substituted amino group and the unsubstituted amino group are as described above), a chlorine atom, or a trifluoromethyl group.

n1 to n4 independently represent an integer of 0 to 3.

When n1 is 2 or more, a plurality of B ² May be the same as, or different from,

when n2 is 2 or more, a plurality of B ⁶ May be the same as, or different from,

when n3 is 2 or more, a plurality of B ⁹ May be the same as, or different from,

when n4 is 2 or more, a plurality of B ¹⁴ May be the same or different from each other.]

As the anthraquinone dye, a compound represented by the formula (I-9) is preferable.

[ solution 2]

[ in the formula (I-9),

R ¹ ～R ⁸ independently of one another, a hydrogen atom, -R ^x 、-NH ₂ 、-NHR ^x 、-NR ^x ₂ 、-SR ^x Or a halogen atom.

R ^x Represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms.]

As the oxazinone (oxazone) pigment, a compound represented by the formula (I-10) is preferred.

[ solution 3]

[ in the formula (I-10),

R ⁹ ～R ¹⁵ independently of each other, a hydrogen atom, -R ^x 、-NH ₂ 、-NHR ^x 、-NR ^x ₂ 、-SR ^x Or a halogen atom.

As the acridine pigment, a compound represented by the formula (I-11) is preferable.

[ solution 4]

[ in the formula (I-11),

R ¹⁶ ～R ²³ independently of each other, a hydrogen atom, -R ^x 、-NH ₂ 、-NHR ^x 、-NR ^x ₂ 、-SR ^x Or a halogen atom.

In the formula (I-9) and the formula (I)-10) and in formula (I-11), as R ^x Examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, propyl, butyl, pentyl and hexyl groups, and examples of the aryl group having 6 to 12 carbon atoms include phenyl, tolyl, xylyl and naphthyl groups.

As the cyanine dye, compounds represented by the formula (I-12) and compounds represented by the formula (I-13) are preferable.

[ solution 5]

[ in the formula (I-12),

D ¹ and D ² Independently of each other, represents a group represented by any one of the formulae (I-12 a) to (I-12 d).

[ solution 6]

n5 represents an integer of 1 to 3. ]

[ solution 7]

[ in the formula (I-13),

D ³ and D ⁴ Independently represent a group represented by any one of the formulae (I-13 a) to (1-13 h).

[ solution 8]

n6 represents an integer of 1 to 3. ]

Specific examples of the dichroic dye include compounds described in Japanese patent laid-open publication No. 2013-210624. From among these dichroic dyes, a dichroic dye in a desired wavelength range may be appropriately selected and used so as to satisfy the above-described formulas (1) to (3) or the formulas (7) to (9).

Among the above-mentioned dichroic dyes, azo dyes have excellent alignment properties because of their high linearity, and are suitable for producing optically anisotropic films having excellent polarization properties. In the present invention, at least 1 of the at least 2 dichroic dyes constituting the optically anisotropic film is preferably an azo dye, and more preferably at least 2 are azo dyes.

The weight average molecular weight of the dichroic dye is usually 300 to 2000, preferably 400 to 1000.

The polymerizable liquid crystal compound (hereinafter also referred to as "polymerizable liquid crystal compound (a)") contained in the composition for forming an optically anisotropic film of the present invention is a compound having at least 1 polymerizable group and having liquid crystallinity. Here, the polymerizable group means a group that participates in a polymerization reaction, and is preferably a photopolymerizable group. The photopolymerizable group refers to a group capable of participating in a polymerization reaction by an active radical, an acid, or the like generated from a polymerization initiator. Examples of the polymerizable group of the polymerizable liquid crystal compound include a vinyl group, a vinyloxy group, a 1-chloroethenyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an epoxyethyl group, and an oxetanyl group. Among these, radical polymerizable groups are preferable, and acryloxy, methacryloxy, vinyloxy, epoxyethyl, and oxetanyl groups are more preferable, and acryloxy groups are still more preferable.

In the present invention, the polymerizable liquid crystal compound is preferably a liquid crystal compound exhibiting a smectic liquid crystal phase. By using a polymerizable liquid crystal compound exhibiting a smectic liquid crystal phase, the polymerizable liquid crystal compound tends to be aligned with a high degree of order, and the absorbance of the optically anisotropic film is easily controlled to the range shown in the above formulas (4) to (6). This makes it possible to form an optically anisotropic film having excellent front color tone in white display. From the viewpoint of achieving a higher degree of alignment order, the liquid crystal state exhibited by the polymerizable liquid crystal compound (a) is more preferably a higher order smectic phase (higher order smectic liquid crystal state). The higher order smectic phase herein means a smectic B phase, a smectic D phase, a smectic E phase, a smectic F phase, a smectic G phase, a smectic H phase, a smectic I phase, a smectic J phase, a smectic K phase and a smectic L phase, and among them, the smectic B phase, the smectic F phase and the smectic I phase are more preferable. The liquid crystal may be a thermotropic liquid crystal or a lyotropic liquid crystal, but the thermotropic liquid crystal is preferable in terms of enabling strict film thickness control. The polymerizable liquid crystal compound (a) may be a monomer, an oligomer polymerized with a polymerizable group, or a polymer.

As the polymerizable liquid crystal compound (a), a liquid crystal compound having at least 1 polymerizable group can be used. Examples of such a polymerizable liquid crystal compound include a compound represented by the following formula (a) (hereinafter also referred to as "polymerizable liquid crystal compound (a)").

U ¹ -V ¹ -W ¹ -(X ¹ -Y ¹ ) _n -X ² -W ² -V ² -U ² (A)

[ in the formula (A),

X ¹ and X ² The aromatic group having a valence of 2 or the alicyclic hydrocarbon group having a valence of 2 independently of each other, wherein a hydrogen atom contained in the aromatic group having a valence of 2 or the alicyclic hydrocarbon group having a valence of 2 may be substituted with a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group or a nitro group, and a carbon atom constituting the aromatic group having a valence of 2 or the alicyclic hydrocarbon group having a valence of 2 may be replaced with an oxygen atom, a sulfur atom or a nitrogen atom. Wherein, X ¹ And X ² At least 1 of them is a1, 4-phenylene group which may have a substituent or a cyclohexane-1, 4-diyl group which may have a substituent.

Y ¹ Is a single bond or a divalent linking group.

n is 1 to 3, and when n is 2 or more, a plurality of X ¹ May be the same or different from each other. X ² Can be associated with a plurality of X ¹ Any or all of which may be the same or different. When n is 2 or more, plural Y' s ¹ May be the same as or different from each other. From the viewpoint of liquid crystallinity, n is preferably2 or more.

U ¹ Represents a hydrogen atom or a polymerizable group.

U ² Represents a polymerizable group.

W ¹ And W ² Independently of one another, a single bond or a divalent linking group.

V ¹ And V ² Independently represent an alkanediyl group having 1 to 20 carbon atoms which may have a substituent, and a-CH group constituting the alkanediyl group ₂ Can be replaced by-O-; -CO-, -S-or NH-.]

In the polymerizable liquid crystal compound (A), X ¹ And X ² Independently of one another, it is preferably 1, 4-phenylene which may have a substituent, or cyclohexane-1, 4-diyl which may have a substituent, X ¹ And X ² At least 1 of them is a1, 4-phenylene group which may have a substituent, or a cyclohexane-1, 4-diyl group which may have a substituent, preferably a trans-cyclohexane-1, 4-diyl group. Examples of the optionally substituted 1, 4-phenylene group which may have a substituent or the cyclohexane-1, 4-diyl group which may have a substituent include an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group and a butyl group, a cyano group, a halogen atom such as a chlorine atom and a fluorine atom. Preferably unsubstituted.

In addition, in the polymerizable liquid crystal compound (a), it is preferable that a portion [ hereinafter also referred to as a partial structure (A1) ] represented by the formula (A1) in the formula (a) is an asymmetric structure in terms of easily exhibiting smectic liquid crystallinity, particularly high-order smectic liquid crystallinity:

-(X ¹ -Y ¹ ) _n -X ² - (A1)

[ in the formula, X ¹ 、Y ¹ 、X ² And n each represents the same meaning as above. Angle (c)

Examples of the polymerizable liquid crystal compound (A) having an asymmetric partial structure (A1) include those having n of 1 and 1X ¹ And X ² A polymerizable liquid crystal compound (A) having a structure different from each other. Further, n is 2 or 2Y ¹ Are of the same structure as each other, 2X ¹ 1X being of the same structure as each other ² Is equal to the 2X ¹ Polymerizable liquid crystal compounds (A) having different structures; 2X ¹ And W in ¹ Bonded X ¹ Is X with another party ¹ And X ² Different structure, another party's X ¹ And X ² A polymerizable liquid crystal compound (A) having the same structure. Further, n is 3 or 3Y ¹ Are of the same structure as each other, 3X ¹ And 1X ² Any 1 of them is a polymerizable liquid crystal compound (A) having a structure different from all the other 3.

Y ¹ Is preferably-CH ₂ CH ₂ -、-CH ₂ O-、-CH ₂ CH ₂ O-, -COO-, -OCOO-, single bond, -N = N-, -CR ^a ＝CR ^b -、-C≡C-、-CR ^a = N-or-CO-NR ^a -。R ^a And R ^b Independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Y is ¹ More preferably-CH ₂ CH ₂ -、-CH ₂ O-, -COO-, -OCOO-, single bond, -N = N-, -CR ^a ＝CR ^b -, -C.ident.C-or-CR ^a = N-, and more preferably-CH ₂ CH ₂ -、-COO-、-CH ₂ O-or a single bond, in the presence of more than one Y ¹ In the case of (2), it is more preferable to react with X ² Bonded Y ¹ is-CH ₂ CH ₂ -or CH ₂ O-, not with X ² Bonded Y ¹ is-CH ₂ CH ₂ -, -COO-or a single bond. At X ¹ And X ² When all of the same structures are used, it is preferable that 2 or more Y's belonging to different bonding systems exist ¹ . In the presence of a plurality of Y's belonging to mutually different bonding modes ¹ In the case of (2), the structure is asymmetric, and thus smectic liquid crystallinity, particularly higher order smectic liquid crystallinity, tends to be easily exhibited.

U ² Is a polymerizable group. U shape ¹ Is a hydrogen atom or a polymerizable group, and is preferably a polymerizable group. U shape ¹ And U ² Preferably, all of them are polymerizable groups, more preferably all of them are photopolymerizable groups, and still more preferably all of them are photo radical polymerizable groups. The polymerizable group may be a polymerizable liquid crystal compoundThe polymerizable group contained in the above-mentioned examples is the same group as that of the above-mentioned examples. U shape ¹ The polymerizable group shown and U ² The polymerizable groups shown may be different from each other, but are preferably the same kind of group, preferably U ¹ And U ² At least one of (a) and (b) is a (meth) acryloyloxy group, more preferably both are (meth) acryloyloxy groups, and still more preferably an acryloyloxy group. The polymerizable group may be in a polymerized state or an unpolymerized state, but is preferably in an unpolymerized state.

As V ¹ And V ² Examples of the alkanediyl group include a methylene group, an ethylene group, a propane-1, 3-diyl group, a butane-1, 4-diyl group, a pentane-1, 5-diyl group, a hexane-1, 6-diyl group, a heptane-1, 7-diyl group, an octane-1, 8-diyl group, a decane-1, 10-diyl group, a tetradecane-1, 14-diyl group, and a eicosane-1, 20-diyl group. V ¹ And V ² Preferably an alkanediyl group having 2 to 12 carbon atoms, more preferably an alkanediyl group having 6 to 12 carbon atoms.

Examples of the optional substituent of the alkanediyl group include a cyano group, a halogen atom such as a chlorine atom or a fluorine atom, and the like, but the alkanediyl group is preferably an unsubstituted, more preferably an unsubstituted, linear alkanediyl group.

W ¹ And W ² Independently of one another, are preferably single bonds, -O-,; -S-, -COO-or-OCOO-, more preferably a single bond or-O-.

The polymerizable liquid crystal compound which easily exhibits smectic liquid crystallinity is preferably a polymerizable liquid crystal compound having an asymmetric molecular structure in the molecular structure, more specifically, a polymerizable liquid crystal compound having the following partial structures (a-a) to (a-i) and exhibiting smectic liquid crystallinity. From the viewpoint of easily exhibiting higher order smectic liquid crystallinity, a partial structure having (A-a), (A-b) or (A-c) is more preferable. In the following (a-a) to (a-i), a bond end (single bond) is represented.

[ solution 9]

Examples of the polymerizable liquid crystal compound (A) include compounds represented by the following formulae (A-1) to (A-25). When the polymerizable liquid crystal compound (A) has a cyclohexane-1, 4-diyl group, the cyclohexane-1, 4-diyl group is preferably a trans-isomer.

[ solution 10]

[ solution 11]

[ solution 12]

Among them, preferred is at least 1 selected from the group consisting of the compounds represented by the formula (A-2), the formula (A-3), the formula (A-4), the formula (A-6), the formula (A-7), the formula (A-8), the formula (A-13), the formula (A-14) and the formula (A-15). The polymerizable liquid crystal compound (a) may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

The polymerizable liquid crystal compound (A) can be produced by a known method described in Lub et al, recl.Trav.Chim.Pays-Bas, 115, 321-328 (1996), japanese patent No. 4719156, or the like.

In the present invention, the optically anisotropic film is preferably formed by containing the polymerizable liquid crystal compound (a), and the composition for forming an optically anisotropic film preferably contains the polymerizable liquid crystal compound (a). When 2 or more polymerizable liquid crystal compounds are contained in the composition for forming an optically anisotropic film, the ratio of the polymerizable liquid crystal compound (a) to the total mass of the polymerizable liquid crystal compounds contained in the composition for forming an optically anisotropic film is preferably 51% by mass or more, more preferably 70% by mass or more, and still more preferably 90% by mass or more. When the ratio of the polymerizable liquid crystal compound (a) is within the above range, an optically anisotropic film having a high degree of orientation order can be easily obtained.

When the composition for forming an optically anisotropic film contains 2 or more polymerizable liquid crystal compounds, at least 1 of them may be the polymerizable liquid crystal compound (a), or all of them may be the polymerizable liquid crystal compound (a). By combining a plurality of polymerizable liquid crystal compounds, the liquid crystal properties can be temporarily maintained even at a temperature not higher than the liquid crystal-to-crystal phase transition temperature.

The content of the polymerizable liquid crystal compound in the composition for forming an optically anisotropic film is preferably 40 to 99.9% by mass, more preferably 60 to 99% by mass, and still more preferably 70 to 99% by mass, based on the solid content of the composition for forming an optically anisotropic film. When the content of the polymerizable liquid crystal compound is within the above range, the orientation of the polymerizable liquid crystal compound tends to be high. In the present specification, the solid component of the composition for forming an optically anisotropic film refers to the total amount of components obtained by removing volatile substances such as solvents from the composition. Hereinafter, the same applies to solid components in other compositions and the like, and the total amount of components obtained by removing volatile substances such as solvents from the subject compositions and the like is meant.

The optically anisotropic film-forming composition may contain a polymerization initiator. The polymerization initiator is a compound capable of initiating a polymerization reaction of a polymerizable liquid crystal compound or the like. As the polymerization initiator, a photopolymerization initiator which generates an active radical or an acid by the action of light is preferable, and a photopolymerization initiator which generates a radical by the action of light is more preferable, from the viewpoint that the polymerization reaction can be initiated under a lower temperature condition. The polymerization initiator may be used alone, or two or more kinds may be used in combination.

As the photopolymerization initiator, a known photopolymerization initiator can be used, and examples of the photopolymerization initiator that generates active radicals include a self-cleavage type photopolymerization initiator and a hydrogen abstraction type photopolymerization initiator.

As the self-cleavage type photopolymerization initiator, a self-cleavage type benzoin-based compound, an acetophenone-based compound, a hydroxyacetophenone-based compound, an α -aminoacetophenone-based compound, an oxime ester-based compound, an acylphosphine oxide-based compound, an azo-based compound, or the like can be used. Further, as the hydrogen abstraction type photopolymerization initiator, hydrogen abstraction type benzophenone-based compounds, benzoin ether-based compounds, benzil ketal-based compounds, dibenzosuberone-based compounds, anthraquinone-based compounds, xanthenone-based compounds, thioxanthone-based compounds, halogenated acetophenone-based compounds, dialkoxyacetophenone-based compounds, halogenated bisimidazole-based compounds, halogenated triazine-based compounds, and the like can be used.

As the photopolymerization initiator generating an acid, iodonium salts, sulfonium salts, and the like can be used.

Among them, from the viewpoint of preventing the dissolution of the dye, a reaction at a low temperature is preferable, and from the viewpoint of reaction efficiency at a low temperature, a self-cleavage type photopolymerization initiator is preferable, and particularly, an acetophenone-based compound, a hydroxyacetophenone-based compound, an α -aminoacetophenone-based compound, and an oxime ester-based compound are preferable.

Specific examples of the photopolymerization initiator include the following.

Benzoin-based compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether;

hydroxyacetophenone-based compounds such as oligomers of 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1, 2-diphenyl-2, 2-dimethoxyethane-1-one, 2-hydroxy-2-methyl-1- [4- (2-hydroxyethoxy) phenyl ] propan-1-one, 1-hydroxycyclohexyl phenyl ketone and 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl ] propan-1-one;

α -aminoacetophenone-based compounds such as 2-methyl-2-morpholino-1- (4-methylthiophenyl) propan-1-one and 2-dimethylamino-2-benzyl-1- (4-morpholinophenyl) butan-1-one;

oxime ester compounds such as 1, 2-octanedione, 1- [4- (phenylthio) -,2- (O-benzoyloxime) ], ethanone, 1- [ 9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl ] -,1- (O-acetyloxime) and the like; acylphosphine oxide-based compounds such as 2,4, 6-trimethylbenzoyldiphenylphosphine oxide and bis (2, 4, 6-trimethylbenzoyl) phenylphosphine oxide;

benzophenone compounds such as benzophenone, methyl benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4 ' -methylbenzophenone sulfide, 3', 4' -tetrakis (t-butylperoxycarbonyl) benzophenone and 2,4, 6-trimethylbenzophenone;

dialkoxyacetophenone-based compounds such as diethoxyacetophenone;

triazine compounds such as 2, 4-bis (trichloromethyl) -6- (4-methoxyphenyl) -1,3, 5-triazine, 2, 4-bis (trichloromethyl) -6- (4-methoxynaphthyl) -1,3, 5-triazine, 2, 4-bis (trichloromethyl) -6- (4-methoxystyryl) -1,3, 5-triazine, 2, 4-bis (trichloromethyl) -6- [ 2- (5-methylfuran-2-yl) vinyl ] -1,3, 5-triazine, 2, 4-bis (trichloromethyl) -6- [ 2- (furan-2-yl) vinyl ] -1,3, 5-triazine, 2, 4-bis (trichloromethyl) -6- [ 2- (4-diethylamino-2-methylphenyl) vinyl ] -1,3, 5-triazine and 2, 4-bis (trichloromethyl) -6- [ 2- (3, 4-dimethoxyphenyl) vinyl ] -1,3, 5-triazine.

The photopolymerization initiator may be appropriately selected from the photopolymerization initiators described above, for example, in terms of the relationship with the polymerizable liquid crystal compound forming the optically anisotropic film.

Further, a commercially available photopolymerization initiator may be used. Examples of commercially available polymerization initiators include Irgacure (registered trademark) 907, 184, 651, 819, 250, 369, 379, 127, 754, OXE01, OXE02, and OXE03 (manufactured by BASF); omnirad BCIM, escapure 1001M, escapure KIP160 (manufactured by IDM Resins B.V.); seikuol (registered trademark) BZ, Z and BEE (manufactured by Seiko chemical Co., ltd.); kayacure (registered trademark) BP100 and UVI-6992 (manufactured by Dow Chemical corporation); adeka Optomer SP-152, N-1717, N-1919, SP-170, adeka Arkls NCI-831, adeka Arkls NCI-930 (manufactured by ADEKA Co., ltd.); TAZ-A and TAZ-PP (available from Siber Hegner, japan); and TAZ-104 (available from Kabushiki Kaisha, co., ltd.).

The content of the polymerization initiator is preferably 0.1 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, still more preferably 0.5 to 10 parts by mass, and particularly preferably 0.5 to 8 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound. When the content of the polymerization initiator is within the above range, the polymerization reaction can proceed without largely disturbing the alignment of the polymerizable liquid crystal compound.

The optically anisotropic film may contain a leveling agent. The leveling agent has a function of adjusting the fluidity of the composition for forming an optically anisotropic film to further flatten a coating film obtained by applying the composition, and specifically, a surfactant is exemplified. The leveling agent is preferably at least 1 selected from leveling agents containing a polyacrylate compound as a main component and leveling agents containing a fluorine atom-containing compound as a main component. The leveling agent may be used alone or in combination of 2 or more.

Examples of the leveling agent containing a polyacrylate compound as a main component include BYK-350, BYK-352, BYK-353, BYK-354, BYK-355, BYK-358N, BYK-361N, BYK-380, BYK-381, and BYK-392 (BYK Chemie Co.).

Examples of the leveling agent containing a fluorine atom-containing compound as a main component include Megafac (registered trademark) R-08, R-30, R-90, F-410, F-411, F-443, F-445, F-470, F-471, F-477, F-479, F-482 and F-483 (DIC (manufactured by KOKAI)); surflon (registered trademark) S-381, S-382, S-383, S-393, SC-101, SC-105, KH-40 and SA-100 (AGC SEMICHEMICAL strain)); e1830, E5844 (DAIKIN FINE CHEMICAL research institute); eftop EF301, eftop EF303, eftop EF351, and Eftop EF352 (Mitsubishi electro chemical corporation)).

When the optically anisotropic film contains a leveling agent, the content thereof is preferably 0.01 to 5 parts by mass, and more preferably 0.05 to 3 parts by mass, per 100 parts by mass of the polymerizable liquid crystal compound. When the content of the leveling agent is within the above range, the polymerizable liquid crystal compound is easily aligned, and unevenness is less likely to occur, and a smoother optically anisotropic film tends to be obtained.

The optically anisotropic film may also contain other additives besides the leveling agent. Examples of the other additives include colorants such as photosensitizers, antioxidants, mold release agents, stabilizers, and bluing agents, flame retardants, and lubricants. When other additives are contained, the content of the other additives is preferably more than 0% and 20% by mass or less, more preferably more than 0% and 10% by mass or less, based on the solid content of the optically anisotropic film-forming composition.

The composition for forming an optically anisotropic film can be produced by a conventionally known method for producing a liquid crystal composition, and can be usually produced by mixing and stirring a polymerizable liquid crystal compound, a dichroic dye, a polymerization initiator used as needed, the above-mentioned additives, and the like. In addition, since the liquid crystal compound exhibiting smectic liquid crystallinity has a high viscosity in general, the viscosity can be adjusted by adding a solvent to the composition for forming an optically anisotropic film, from the viewpoint of improving the coating properties of the composition and facilitating the formation of an optically anisotropic film.

The solvent may be appropriately selected depending on the solubility of the polymerizable liquid crystalline compound, the dichroic dye, and the like used, and is preferably a solvent that can completely dissolve the components and is inactive to the polymerization reaction.

Examples of the solvent include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol methyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ -butyrolactone or propylene glycol methyl ether acetate, and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; aromatic hydrocarbon solvents such as toluene and xylene, and nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; and chlorine-containing solvents such as chloroform and chlorobenzene. These solvents may be used alone, or 2 or more of them may be used in combination.

The content of the solvent is preferably 50 to 98 parts by mass, and more preferably 70 to 95 parts by mass, based on 100 parts by mass of the optically anisotropic film-forming composition. Therefore, the solid content of 100 parts by mass of the composition for forming an optically anisotropic film is preferably 2 to 50 parts by mass. When the solid content is 50 parts by mass or less, the viscosity of the optically anisotropic film-forming composition is low, and therefore the thickness of the film becomes substantially uniform, and unevenness tends not to occur easily. The solid content may be appropriately determined in consideration of the thickness of the optically anisotropic film to be produced.

The optically anisotropic film of the present invention is a film obtained by curing a polymerizable liquid crystal compound and at least 2 kinds of dichroic dyes in a state of being aligned in a direction perpendicular to the film plane, and it is preferable that the following formula (14) is satisfied, in general, when an arbitrary direction in the optically anisotropic film plane is defined as an x-axis, a direction orthogonal to the x-axis in the film plane is defined as a y-axis, and a film thickness direction orthogonal to the x-axis and the y-axis is defined as a z-axis.

Az＞(Ax+Ay)/2 (14)

[ Ax, ay, and Az are each the absorbance at the absorption maximum wavelength of the dichroic dye in the optically anisotropic film,

ax represents the absorbance of linearly polarized light vibrating in the x-axis direction,

ay represents the absorbance of linearly polarized light vibrating in the y-axis direction,

az represents the absorbance of linearly polarized light vibrating in the z-axis direction. Angle (c)

Ax can be measured by applying linearly polarized light oscillating in the x-axis direction to the film surface from the z-axis direction. Ay can be measured by applying linearly polarized light oscillating in the y-axis direction to the film surface from the z-axis direction. Az can be measured, for example, by allowing linearly polarized light oscillating in the z-axis direction to enter perpendicularly from the x-y plane direction toward the film side surface, that is, when the optically anisotropic film is set to the x-y plane, toward the side surface (thickness direction).

By using a compound that forms a smectic liquid crystal phase, particularly a higher order smectic liquid crystal phase, as the polymerizable liquid crystal compound, it is easy to become an optically anisotropic film in which the polymerizable liquid crystal compound and at least 2 kinds of dichroic dyes are highly orderly oriented in a perpendicular direction with respect to the film plane, and an optically anisotropic film that is excellent in the transmittance of light from the front direction and can efficiently absorb light of a specific wavelength from the oblique direction can be obtained.

The thickness of the optically anisotropic film may be, for example, 0.05 μm to 5 μm, preferably 0.1 μm or more, more preferably 0.3 μm or more, and preferably 3 μm or less, more preferably 2 μm or less. When the thickness of the optically anisotropic film is not less than the lower limit, light absorption from an oblique direction is good, and the oblique color tone in white display is easily improved. When the thickness is not more than the upper limit, the alignment of the polymerizable liquid crystal compound and the dichroic dye is not easily disturbed, and high transmittance in the front direction can be secured, and thinning when incorporated in a display device or the like can be expected. The thickness of the optically anisotropic film can be measured by a laser microscope, a film thickness meter, or the like, and the thickness of each layer constituting the laminate including the optically anisotropic film is measured in the same manner as described below.

In the present invention, the optically anisotropic film is preferably a liquid crystal cured film having a high degree of alignment order. The liquid crystal cured film having a high degree of orientation order can obtain a Bragg peak derived from a high-order structure such as a hexagonal phase or a crystal phase in X-ray diffraction measurement. The bragg peak is a peak derived from a plane periodic structure of molecular orientation. Thus, the optically anisotropic film of the present invention preferably exhibits bragg peaks in X-ray diffraction measurement. That is, in the optically anisotropic film of the present invention, it is preferable that the polymerizable liquid crystal compound or a polymer thereof is oriented so that the film shows a bragg peak in X-ray diffraction measurement. Preferred molecular orientations in the present invention have a plane period spacing of

The optically anisotropic film of (1). The high degree of alignment order of the bragg peak can be achieved by controlling the kind of the polymerizable liquid crystal compound used, the kind and amount of the dichroic dye, and the kind and amount of the polymerization initiator.

In the present invention, the optically anisotropic film can be obtained by orienting the absorption axis of the dichroic dye in a direction orthogonal to the film surface. The direction of the absorption axis of the dichroic dye of such a host-guest type optically anisotropic film is generally controlled by the direction in which the polymerizable liquid crystal compound is aligned. By setting the orientation direction of the molecular long axis of the polymerizable liquid crystal compound to a direction orthogonal to the film surface, the absorption axis of the dichroic dye can be generally oriented in the direction orthogonal to the film surface. The orientation direction of the polymerizable liquid crystal compound can be controlled by the properties of the base material or the orientation film to which the composition for forming an optically anisotropic film containing the polymerizable liquid crystal compound and the dichroic dye is applied, the properties of the polymerizable liquid crystal compound, and the like.

The optically anisotropic film of the present invention can be produced, for example, by a method comprising the steps of,

a step of forming a coating film of a composition for forming an optically anisotropic film, which comprises a polymerizable liquid crystal compound and at least 2 kinds of dichroic dyes, on a substrate with or without an alignment film interposed therebetween,

A step of drying the obtained coating film to obtain a dried coating film, and

and curing the polymerizable liquid crystal compound and the dichroic dye in the coating film in a state of being aligned in a direction perpendicular to the plane of the coating film.

Examples of the substrate include a glass substrate and a film substrate, and a resin film substrate is preferable from the viewpoint of processability. Examples of the resin constituting the film substrate include polyolefins such as polyethylene, polypropylene, and norbornene polymers; a cycloolefin resin; polyvinyl alcohol; polyethylene terephthalate; polymethacrylates; a polyacrylate; cellulose esters such as triacetyl cellulose, diacetyl cellulose, and cellulose acetate propionate; polyethylene naphthalate; a polycarbonate; polysulfones; polyether sulfone; a polyether ketone; plastics such as polyphenylene sulfide and polyphenylene oxide. The resin can be formed into a film by a known method such as a solvent casting method or a melt extrusion method to prepare a substrate. The surface of the base material may have a protective layer made of an acrylic resin, a methacrylic resin, an epoxy resin, an oxetane resin, a urethane resin, a melamine resin, or the like, or may be subjected to a surface treatment such as a mold release treatment such as a silicone treatment, a corona treatment, a plasma treatment, or the like.

Commercially available products can be used as the substrate. Examples of commercially available cellulose ester substrates include cellulose ester substrates manufactured by FUJITAC film, and the like; cellulose ester substrates manufactured by Konica Minolta Opto Ltd. "KC8UX2M", "KC8UY" and "KC4UY", and the like. Examples of commercially available cycloolefin resins include cycloolefin resins manufactured by Ticona corporation (de), such as "Topas (registered trademark)"; a cycloolefin resin manufactured by JSR corporation such as "ARTON (registered trademark)"; cycloolefin resins manufactured by ZEON corporation of japan such as "ZEONOR (registered trademark)" and "ZEONEX (registered trademark)"; a cycloolefin resin manufactured by Mitsui chemical corporation such as "APEL" (registered trademark). Commercially available cycloolefin resin substrates can also be used. Examples of commercially available cycloolefin resin substrates include cycloolefin resin substrates manufactured by waterlogged chemical industries, ltd.s.c. "Escena (registered trademark)" and "SCA40 (registered trademark)"; a cycloolefin resin base material manufactured by Optes corporation such as "ZEONOR FILM (registered trademark)"; a cycloolefin resin base material manufactured by JSR corporation such as "ARTON FILM (registered trademark)".

The thickness of the substrate is not particularly limited, but is usually 5 to 300. Mu.m, and may be 10 to 150. Mu.m.

In the present invention, the optically anisotropic film may be formed on the alignment film. The alignment film has an alignment regulating force for aligning the liquid crystal of the polymerizable liquid crystal compound in a desired direction, and by applying the composition for forming an optically anisotropic film to the alignment film, an optically anisotropic film having excellent alignment accuracy can be easily obtained. The alignment film preferably has solvent resistance that does not dissolve due to application of the composition for forming an optically anisotropic film or the like, and heat resistance that is used for removal of the solvent and heat treatment for alignment of the polymerizable liquid crystal compound. Examples of the alignment film include an alignment film containing a compound capable of promoting the alignment of the polymerizable liquid crystal compound in a direction perpendicular to the film plane (hereinafter referred to as a "vertical alignment promoting compound"), an alignment film containing an alignment polymer, and the like.

An alignment film containing a vertical alignment promoting compound is generally obtained by applying a composition in which a vertical alignment promoting compound is dissolved in a solvent (hereinafter, also referred to as a "composition containing a vertical alignment promoting compound") to a substrate and removing the solvent. Examples of the solvent include water, an alcohol solvent, and a mixed solvent of water and an alcohol, and the solvent is the same as the solvent used in the optically anisotropic film-forming composition exemplified above.

Examples of the vertical alignment accelerating compound include nonionic silane compounds such as silicon polymers such as polysilanes, silicone resins such as silicone oils and silicone resins, silicone oligomers, and organic-inorganic silane compounds (more specifically, silane coupling agents) such as silsesquioxanes and alkoxysilanes, and silane coupling agents are preferable.

The concentration of the vertical alignment promoting compound in the composition containing the vertical alignment promoting compound may be in a range in which the vertical alignment promoting compound can be completely dissolved in the solvent, but is preferably 0.1 to 20%, more preferably about 0.1 to 10% in terms of solid content, with respect to the solution.

The alignment film containing an alignment polymer can be generally obtained by applying a composition in which an alignment polymer is dissolved in a solvent (hereinafter, also referred to as an "alignment polymer composition") to a substrate and removing the solvent, or by applying an alignment polymer composition to a substrate and removing the solvent and rubbing (rubbing method). The solvent may be the same as the solvent used in the optically anisotropic film forming composition exemplified above.

Examples of the orientation polymer include polyamides having an amide bond in the molecule, gelatins, polyimides having an imide bond in the molecule, and polyamic acids, polyvinyl alcohols, alkyl-modified polyvinyl alcohols, polyacrylamides, polyoxazoles, polyethyleneimines, polystyrenes, polyvinylpyrrolidones, polyacrylic acids, and polyacrylates as hydrolysates thereof. Among them, polyvinyl alcohol is preferable. The alignment polymer may be used alone or in combination of 2 or more.

The concentration of the orientation polymer in the orientation polymer composition may be in a range in which the orientation polymer material can be completely dissolved in the solvent, but is preferably 0.1 to 20%, and more preferably about 0.1 to 10% in terms of solid content with respect to the solution.

As the alignment polymer composition, a commercially available alignment film material can be used as it is. Examples of commercially available alignment film materials include suniver (registered trademark, manufactured by nippon chemical industry corporation), OPTOMER (registered trademark, manufactured by JSR corporation), and the like.

Examples of the method for applying the alignment polymer composition to the substrate include known methods such as spin coating, extrusion, gravure coating, die coating, bar coating, coating methods such as a size applicator method, and printing methods such as a flexographic method.

Examples of the method for removing the solvent contained in the oriented polymer composition include a natural drying method, a forced air drying method, a heat drying method, a reduced pressure drying method, and the like.

In order to impart an alignment regulating force to the alignment film, rubbing treatment (rubbing method) may be performed as necessary. As a method for imparting orientation restriction by a rubbing method, there is a method in which a film of an oriented polymer formed on the surface of a base material by applying an oriented polymer composition to the base material and annealing is brought into contact with a rubbing roll around which a rubbing cloth is wound and rotated. When masking is performed during rubbing, a plurality of regions (patterns) having different alignment directions may be formed in the alignment film.

The method of applying the composition for forming an optically anisotropic film to a substrate or the like includes the same methods as those exemplified as the method of applying the oriented polymer composition to a substrate.

In the case where the composition for optically anisotropic film formation contains a solvent, the solvent is usually removed from the applied composition. Examples of the method for removing the solvent include a natural drying method, a forced air drying method, a heat drying method, and a reduced pressure drying method. The dried coating film is preferably dried so that the residual solvent in the optically anisotropic film is 1 wt% or less with respect to the total mass of the optically anisotropic film. The conditions such as the drying temperature and the drying time can be appropriately determined depending on the composition of the composition for forming an optically anisotropic film, the material of the film base material, and the like.

In general, the polymerizable liquid crystal compound in the coating film is heated to a temperature equal to or higher than a temperature at which the polymerizable liquid crystal compound is converted into a liquid crystal state or a solution state, and then cooled to a temperature at which liquid crystal alignment is performed, whereby the polymerizable liquid crystal compound is aligned together with the dichroic dye to form a liquid crystal phase.

The temperature at which the polymerizable liquid crystal compound in the coating film is aligned may be determined by texture observation or the like using a composition containing the polymerizable liquid crystal compound in advance. In addition, the removal of the solvent and the alignment of the liquid crystal may be performed simultaneously. The temperature at this time is also determined depending on the solvent to be removed and the kind of polymerizable liquid crystal compound to be used, but is preferably in the range of 50 to 200 ℃ and more preferably in the range of 80 to 130 ℃.

The polymerizable liquid crystal compound is polymerized and cured while maintaining the liquid crystal state of the polymerizable liquid crystal compound, thereby forming an optically anisotropic film as a cured film of the polymerizable liquid crystal composition. The polymerization method is preferably a photopolymerization method. In the photopolymerization, the light (active energy ray) to be irradiated to the dried coating film can be appropriately selected depending on the kind of the polymerizable liquid crystal compound contained in the dried coating film (particularly, the kind of the polymerizable group contained in the polymerizable liquid crystal compound), the kind of the polymerization initiator, the amount thereof, and the like. A liquid crystal cured film containing a polymerizable liquid crystal compound that polymerizes while maintaining a liquid crystal phase of a (higher order) smectic phase has higher polarization performance than a conventional liquid crystal cured film obtained by polymerizing a polymerizable liquid crystal compound or the like while maintaining a liquid crystal phase of a nematic phase, and has better polarization performance and film strength than a film coated with only a dichroic dye or a lyotropic liquid crystal.

Examples of the light source of the active energy ray include a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a xenon lamp, a halogen lamp, a carbon arc lamp, a tungsten lamp, a gallium lamp, an excimer laser, an LED light source emitting light in a wavelength range of 380 to 440nm, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, a metal halide lamp, and the like. A light source having a light emission distribution at a wavelength of 400nm or less, such as a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a chemical lamp, a black-light lamp, a microwave-excited mercury lamp, or a metal halide lamp, is preferable, and ultraviolet rays in a direction parallel to the normal line of the substrate are more preferable.

The irradiation energy of the active energy ray is preferably such that the irradiation intensity in a wavelength region effective for activation of the polymerization initiator is 10 to 5000mJ/cm ² The above-mentioned embodiment is more preferably 100 to 2000mJ/cm ² 。

< laminate >

The laminate of the present invention comprises the optically anisotropic film of the present invention, a polarizing film, and a horizontally oriented phase difference film. By laminating the optically anisotropic film of the present invention on a laminate which includes a polarizing film and a horizontally oriented retardation film and functions as a circularly polarizing plate, the difference in color between the front color tone and the oblique color tone can be effectively reduced at the time of white display, and excellent image display characteristics can be exhibited when incorporated in an organic EL display device or the like.

The polarizing film constituting the laminate of the present invention is a film having a function of extracting linearly polarized light from incident natural light. Examples of the polarizing film include a stretched film in which a dye having absorption anisotropy is adsorbed, a film coated with a dye having absorption anisotropy as a polarizing plate, and the like. Examples of the dye having absorption anisotropy include dichroic dyes.

A film including a stretched film having a dye having absorption anisotropy adsorbed thereon as a polarizing plate is generally produced through a step of uniaxially stretching a polyvinyl alcohol resin film, a step of adsorbing a dichroic dye by dyeing the polyvinyl alcohol resin film with the dichroic dye, a step of treating the polyvinyl alcohol resin film having the dichroic dye adsorbed thereon with an aqueous boric acid solution, and a step of washing with water after the treatment with the aqueous boric acid solution.

The polyvinyl alcohol resin is obtained by saponifying a polyvinyl acetate resin. As the polyvinyl acetate-based resin, polyvinyl acetate which is a homopolymer of vinyl acetate may be used, and a copolymer of vinyl acetate and another monomer copolymerizable therewith may be used. Examples of the other monomer copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

The saponification degree of the polyvinyl alcohol resin is usually about 85 to 100 mol%, and preferably 98 mol% or more. The polyvinyl alcohol resin may be modified, and for example, polyvinyl formal or polyvinyl acetal modified with an aldehyde may be used. The polyvinyl alcohol resin has an average polymerization degree of usually about 1000 to 10000, preferably 1500 to 5000.

A film obtained by forming such a polyvinyl alcohol resin film is used as a raw material film of a polarizing film. The method for forming the polyvinyl alcohol resin film is not particularly limited, and a known method can be used for forming the film. The thickness of the polyvinyl alcohol-based material film may be, for example, about 10 to 150. Mu.m.

The uniaxial stretching of the polyvinyl alcohol resin film may be performed before, simultaneously with, or after the dyeing with the dichroic dye. In the case of uniaxial stretching after dyeing, the uniaxial stretching may be performed before boric acid treatment or may be performed during boric acid treatment. In addition, uniaxial stretching may be performed in these plural stages. In the case of uniaxial stretching, the stretching may be performed uniaxially between rolls having different peripheral speeds, or may be performed uniaxially using a heat roll. The uniaxial stretching may be dry stretching in which stretching is performed in the air, or wet stretching in which stretching is performed in a state where the polyvinyl alcohol resin film is swollen with a solvent. The stretch ratio is usually about 3 to 8 times.

The dyeing of the polyvinyl alcohol resin film with the dichroic dye can be performed, for example, by a method of immersing the polyvinyl alcohol resin film in an aqueous solution containing the dichroic dye.

Specifically, iodine or a dichroic organic dye is used as the dichroic dye. Examples of the dichroic organic dye include a dichroic direct dye containing a disazo compound such as c.i. direct RED 39, and a dichroic direct dye containing a compound such as a trisazo compound or a tetraazo compound. The polyvinyl alcohol resin film is preferably subjected to an immersion treatment in water before the dyeing treatment.

When iodine is used as the dichroic dye, a method of immersing a polyvinyl alcohol resin film in an aqueous solution containing iodine and potassium iodide to dye the film is generally employed. The content of iodine in the aqueous solution is usually about 0.01 to 1 part by mass per 100 parts by mass of water. The content of potassium iodide is usually about 0.5 to 20 parts by mass relative to 100 parts by mass of water. The temperature of the aqueous solution used in dyeing is usually about 20 to 40 ℃. The immersion time (dyeing time) in the aqueous solution is usually about 20 to 1800 seconds.

On the other hand, when a dichroic organic dye is used as the dichroic dye, a method of immersing the polyvinyl alcohol-based resin film in an aqueous solution containing a water-soluble dichroic dye to dye the film is generally used. The content of the dichroic organic dye in the aqueous solution is usually 1 × 10 with respect to 100 parts by mass of water ^-4 About 10 parts by mass, preferably 1X 10 ^-3 1 part by mass, more preferably 1X 10 ^-3 ～1×10 ^-2 And (4) parts by mass. The aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing assistant. The temperature of the aqueous solution of the dichroic dye used for dyeing is usually about 20 to 80 ℃. The immersion time (dyeing time) in the aqueous solution is usually about 10 to 1800 seconds.

The boric acid treatment after dyeing with the dichroic dye can be generally performed by a method of immersing the dyed polyvinyl alcohol resin film in an aqueous boric acid solution. The boric acid content in the aqueous boric acid solution is usually about 2 to 15 parts by mass, preferably 5 to 12 parts by mass, relative to 100 parts by mass of water. When iodine is used as the dichroic dye, the aqueous boric acid solution preferably contains potassium iodide, and the content of potassium iodide in this case is usually about 0.1 to 15 parts by mass, preferably 5 to 12 parts by mass, per 100 parts by mass of water. The immersion time in the aqueous boric acid solution is usually about 60 to 1200 seconds, preferably 150 to 600 seconds, and more preferably 200 to 400 seconds. The temperature of the boric acid treatment is usually 50 ℃ or more, preferably 50 to 85 ℃, and more preferably 60 to 80 ℃.

The polyvinyl alcohol resin film after the boric acid treatment is usually subjected to a water washing treatment. The water washing treatment can be performed, for example, by a method of immersing the boric acid-treated polyvinyl alcohol resin film in water. The temperature of water in the water washing treatment is usually about 5 to 40 ℃. The immersion time is usually about 1 to 120 seconds.

After washing with water, drying treatment was performed to obtain a polarizing film (polarizing plate). The drying treatment can be performed using, for example, a hot air dryer or a far infrared heater. The temperature of the drying treatment is usually about 30 to 100 ℃ and preferably 50 to 80 ℃. The time for the drying treatment is usually about 60 to 600 seconds, preferably 120 to 600 seconds. The moisture content of the polarizing film is reduced to a practical level by the drying treatment. The water content is usually about 5 to 20% by mass, preferably 8 to 15% by mass. When the water content is within the above range, a polarizing film having appropriate flexibility and excellent thermal stability can be obtained.

The thickness of the polarizing film obtained by uniaxially stretching the polyvinyl alcohol resin film, dyeing with a dichroic dye, boric acid treatment, washing with water, and drying as described above is preferably 5 to 40 μm.

Examples of the film coated with a dye having absorption anisotropy include a film coated with a composition containing a dichroic dye having liquid crystallinity, a composition containing a dichroic dye and a polymerizable liquid crystal, and the like.

Although a film coated with a dye having absorption anisotropy is preferable, if it is too thin, the strength tends to decrease, and the processability tends to be poor. The thickness of the film is usually 20 μm or less, preferably 5 μm or less, and more preferably 0.5 to 3 μm.

Specific examples of the film coated with a dye having absorption anisotropy include films described in japanese unexamined patent application publication No. 2012-33249 and the like.

A transparent protective layer may be laminated on one surface or both surfaces of the polarizing film obtained as described above, for example, via an adhesive layer. The transparent protective layer can contribute to prevention of shrinkage and expansion of the polarizing film, prevention of deterioration of the polarizing film due to temperature, humidity, ultraviolet rays, and the like, prevention of scratching of the polarizing film, and the like. As the protective film, a transparent film similar to the resin film exemplified above as a base material that can be used in the production of the optically anisotropic film can be used.

The laminate of the present invention comprises a horizontally oriented retardation film. The horizontally aligned retardation film that can constitute the laminate of the present invention is a retardation film that is aligned in the horizontal direction with respect to the in-plane direction of the film, and may be, for example, a stretched film, a cured product of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound (hereinafter also referred to as "composition for forming a horizontally aligned liquid crystal cured film"), or a cured product obtained by curing a polymerizable liquid crystal compound in a state of being aligned in the horizontal direction with respect to the plane of the retardation film (hereinafter also referred to as "horizontally aligned liquid crystal cured film").

In the present invention, the horizontally oriented retardation film preferably satisfies the following formulae (15) and (16).

ReA(450)/ReA(550)≤1.0 (15)

1.0≤ReA(650)/ReA(550) (16)

In expressions (15) and (16), reA (λ) represents an in-plane retardation value of the horizontally oriented retardation film at a wavelength λ nm, and ReA (λ) = (nxA (λ) -nyA (λ)) × dA (in the expressions, nxA (λ) represents a main refractive index at a wavelength λ nm in the horizontally oriented retardation film plane, nyA (λ) represents a refractive index at a wavelength λ nm in a direction orthogonal to the direction of nxA in the same plane as nxA, and dA represents a film thickness of the horizontally oriented retardation film). Angle (c)

When the horizontally oriented retardation film satisfies the expressions (15) and (16), the horizontally oriented retardation film exhibits so-called reverse wavelength dispersion in which the in-plane retardation value at a short wavelength is smaller than the in-plane retardation value at a long wavelength. For example, when such a horizontally oriented retardation film is combined with the optically anisotropic film of the present invention, it is possible to exhibit an excellent effect of improving the front color tone and the oblique color tone in white display when incorporated in an organic EL display device, and also improving the front reflection color tone in black display. Since the reverse wavelength dispersibility is improved and the effect of improving the reflection color tone in the front direction of the horizontally oriented retardation film can be further improved, the amount of the re a (450)/the re a (550) is preferably 0.70 or more, more preferably 0.78 or more, further preferably 0.92 or less, more preferably 0.90 or less, further preferably 0.87 or less, particularly preferably 0.86 or less, and particularly preferably 0.85 or less. ReA (650)/ReA (550) is preferably 1.01 or more, more preferably 1.02 or more.

The effect of the improvement (change) of the "front reflection color tone at the time of black display" described above means an effect of improving the front reflection color tone at the time of black display (that is, an effect of reducing light leakage when viewed from the front direction at the time of black display) when the optical anisotropic film and the horizontally oriented retardation film are applied in combination to the display device.

The in-plane retardation value can be adjusted by the thickness dA of the horizontal alignment retardation film. Since the in-plane retardation value is determined by the above expression of ReA (λ) = (nxA (λ) -nyA (λ)) × dA, in order to obtain a desired in-plane retardation value (ReA (λ): the in-plane retardation value of the horizontally oriented retardation film at the wavelength λ (nm)), the three-dimensional refractive index and the film thickness dA may be adjusted.

Further, the horizontally oriented retardation film preferably satisfies the following formula (17).

120nm≤ReA(550)≤170nm (17)

In the formula (17), reA (. Lamda.) is as defined above. Angle (c)

When the in-plane retardation of the horizontally oriented retardation film, reA (550), is within the range of formula (17), the effect of enhancing the front reflection color tone at the time of black display (the effect of suppressing coloring) becomes remarkable when a laminate (elliptically polarizing plate) comprising the horizontally oriented retardation film is applied to an organic EL display device. A more preferable range of the in-plane phase difference value is 130 nm. Ltoreq. ReA (550). Ltoreq.150 nm.

The horizontally aligned retardation film is preferably a horizontally aligned liquid crystal cured film in view of easily controlling a desired retardation of the retardation film and making it thinner. As the polymerizable liquid crystal compound used for forming the horizontally aligned liquid crystal cured film, a polymerizable liquid crystal compound conventionally known in the field of retardation films can be used.

The polymerizable liquid crystal compound forming the horizontally aligned liquid crystal cured film is a liquid crystal compound having at least 1 polymerizable group. As the polymerizable liquid crystal compound, a polymerizable liquid crystal compound exhibiting a positive wavelength dispersibility and a polymerizable liquid crystal compound exhibiting a reverse wavelength dispersibility are generally exemplified by a polymer (cured product) obtained by polymerizing the polymerizable liquid crystal compound alone in a state of being aligned in a specific direction. In the present invention, only one kind of the polymerizable liquid crystal compound may be used, or two kinds of the polymerizable liquid crystal compounds may be used in combination. In the laminate of the present invention, the horizontally oriented retardation film is preferably a cured film of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound exhibiting so-called reverse wavelength dispersibility, from the viewpoint of easily improving optical characteristics as a laminate.

In the present invention, the polymerizable group of the polymerizable liquid crystal compound forming the horizontally aligned liquid crystal cured film is preferably a photopolymerizable group. Examples of the photopolymerizable group include polymerizable groups similar to those which the polymerizable liquid crystal compound (a) forming the optically anisotropic film can have. Among them, (meth) acryloyl, vinyloxy, epoxyethyl and oxetanyl groups are preferable, and acryloyl is more preferable.

The liquid crystallinity exhibited by the polymerizable liquid crystal compound forming the horizontally aligned liquid crystal cured film may be a thermotropic liquid crystal or a lyotropic liquid crystal, but a thermotropic liquid crystal is preferable in terms of enabling tight film thickness control. The phase-ordered structure of the thermotropic liquid crystal may be a nematic liquid crystal, a smectic liquid crystal, or a discotic liquid crystal. The polymerizable liquid crystal compounds forming the horizontally aligned liquid crystal cured film may be used alone or in combination of two or more.

A polymerizable liquid crystal compound having a so-called T-shaped or H-shaped molecular structure tends to exhibit reverse wavelength dispersibility when polymerized and cured, and a polymerizable liquid crystal compound having a T-shaped molecular structure tends to exhibit a stronger reverse wavelength dispersibility.

The polymerizable liquid crystal compound exhibiting reverse wavelength dispersibility is preferably a compound having the following characteristics (a) to (D).

(A) Are compounds capable of forming a nematic or smectic phase.

(B) The polymerizable liquid crystal compound has pi electrons in the long axis direction (a).

(C) Has pi electrons in the direction [ the crossing direction (b) ] crossing the longitudinal direction (a).

(D) The pi electron density in the major axis direction (a) and the pi electron density in the cross direction (b) are in the relationship of formula (iii) [ i.e., the pi electron density in the cross direction (b) is greater than the pi electron density in the major axis direction (a) ].

0≤〔D(πa)/D(πb)〕＜1 (iii)

The pi electron density in the long axis direction (a) is a pi electron density in the long axis direction (a) of the polymerizable liquid crystal compound defined by the following formula (i) in which N (pi a) represents the total of pi electrons present in the long axis direction (a), and N (Aa) represents the total of molecular weights present in the long axis direction (a):

D(πa)＝N(πa)/N(Aa) (i)

the pi electron density in the cross direction (b) is a pi electron density in the cross direction (b) of the polymerizable liquid crystal compound defined by the following formula (ii) in which N (pi b) represents the total of pi electrons present in the cross direction (b), N (Ab) represents the total of molecular weights present in the cross direction (b), and:

D(πb)＝N(πb)/N(Ab) (ii)

as described above, a polymerizable liquid crystal compound having pi electrons in the long axis and the direction intersecting with the long axis is generally likely to have a T-shaped structure.

In the above features (a) to (D), the major axis direction (a) and the pi-electron number N are defined as follows.

In the case of a compound having a rod-like structure, for example, the longitudinal direction (a) is a longitudinal direction of the rod.

The number of pi electrons N (pi a) existing in the major axis direction (a) does not include pi electrons lost by the polymerization reaction.

The number of pi electrons N (pi a) present in the major axis direction (a) is the total number of pi electrons on the major axis and pi electrons conjugated thereto, and includes, for example, the number of pi electrons present in a ring which is present in the major axis direction (a) and satisfies the scherrer's law.

The number of pi electrons N (pi b) existing in the crossing direction (b) does not include pi electrons lost by the polymerization reaction.

The polymerizable liquid crystal compound satisfying the above characteristics has a mesogenic structure in the long axis direction. The mesomorphic structure allows a liquid crystal phase (nematic phase, smectic phase) to be expressed.

By heating the polymerizable liquid crystal compound satisfying the above (a) to (D) to a phase transition temperature or higher, a nematic phase and a smectic phase can be formed. In the nematic phase or smectic phase in which the polymerizable liquid crystal compound is aligned, the polymerizable liquid crystal compound is generally aligned so that the long axis directions of the polymerizable liquid crystal compound are parallel to each other, and the long axis direction is the alignment direction of the nematic phase or smectic phase. When such a polymerizable liquid crystal compound is polymerized in a nematic phase or a smectic phase in the form of a film, a polymer film containing a polymer polymerized in a state of being aligned in the long axis direction (a) can be formed. The polymer film absorbs ultraviolet light by pi electrons in the major axis direction (a) and pi electrons in the cross direction (b). Here, the absorption maximum wavelength of ultraviolet light absorbed by pi electrons in the cross direction (b) is λ bmax. The λ bmax is usually 300nm to 400nm. Since the density of pi electrons satisfies the above formula (iii) and the pi electron density in the cross direction (b) is higher than the pi electron density in the long axis direction (a), the polymer film is formed such that the absorption of linearly polarized ultraviolet rays (wavelength λ bmax) having a vibration plane in the cross direction (b) is higher than the absorption of linearly polarized ultraviolet rays (wavelength λ bmax) having a vibration plane in the long axis direction (a). This ratio (ratio of absorbance in the cross direction (b) of the linearly polarized ultraviolet light to absorbance in the longitudinal direction (a)) is, for example, greater than 1.0, preferably 1.2 or more, usually 30 or less, for example 10 or less.

In general, most of the polymerizable liquid crystal compounds having the above characteristics exhibit a birefringence of a polymer when polymerized in a state of being aligned in one direction, and exhibit reverse wavelength dispersibility. Specifically, for example, a compound represented by the following formula (X) (hereinafter, also referred to as "polymerizable liquid crystal compound (X)") can be mentioned.

[ solution 13]

In the formula (X), ar represents a divalent group having an aromatic group which may have a substituent. Examples of the aromatic group include those exemplified by (Ar-1) to (Ar-23) described later. In addition, ar may have 2 or more aromatic groups. The aromatic group may contain at least 1 or more of a nitrogen atom, an oxygen atom, and a sulfur atom. When the number of the aromatic groups contained in Ar is 2 or more, 2 or more of the aromatic groups may be bonded to each other with a divalent bonding group such as a single bond, -CO-O-, -O-, or the like.

In the formula (X), G ¹ And G ² Each independently represents a divalent aromatic group or a divalent alicyclic hydrocarbon group. Here, the hydrogen atom contained in the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, or a nitro group, and the carbon atom constituting the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom, or a nitrogen atom.

In the formula (X), L ¹ 、L ² 、B ¹ And B ² Each independently is a single bond or a divalent linking group.

In the formula (X), k and l each independently represent an integer of 0 to 3, and satisfy the relationship of 1. Ltoreq. K + l. Here, in the case of 2. Ltoreq. K + l, B ¹ And B ² 、G ¹ And G ² Each may be the same or different.

In the formula (X), E ¹ And E ² Each independently represents an alkanediyl group having 1 to 17 carbon atoms, and more preferably an alkanediyl group having 4 to 12 carbon atoms. Further, a hydrogen atom contained in an alkanediyl group may be substituted with a halogen atom, and-CH contained in the alkanediyl group ₂ -may be replaced by-O-, -S-, -C (= O) -.

In the formula (X), P ¹ And P ² Independently of each other, a polymerizable group or a hydrogen atom, and at least 1 is a polymerizable group.

G ¹ And G ² Each independently is preferably a1, 4-benzenediyl group which may be substituted with at least 1 substituent selected from a halogen atom and an alkyl group having 1 to 4 carbon atoms, or a1, 4-cyclohexanediyl group which may be substituted with at least 1 substituent selected from a halogen atom and an alkyl group having 1 to 4 carbon atoms, more preferably a1, 4-benzenediyl group which is substituted with a methyl group, an unsubstituted 1, 4-benzenediyl group, or an unsubstituted 1, 4-trans-cyclohexanediyl group, and particularly preferably an unsubstituted 1, 4-benzenediyl group or an unsubstituted 1, 4-trans-cyclohexanediyl group.

In addition, it is preferable that a plurality of G's exist ¹ And G ² Wherein at least 1 is a divalent alicyclic hydrocarbon group, and is more preferably a group represented by formula (I) and (II) ¹ Or L ² Bonded G ¹ And G ² Wherein at least 1 is a divalent alicyclic hydrocarbon group.

L ¹ And L ² Each independently preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R ^a1 OR ^a2 -、-R ^a3 COOR ^a4 -、-R ^a5 OCOR ^a6 -、-R ^a7 OC＝OOR ^a8 -、-N＝N-、-CR ^c ＝CR ^d -, or-C.ident.C-. Here, R ^a1 ～R ^a8 Each independently represents a single bond or an alkylene group having 1 to 4 carbon atoms, R ^c And R ^d Represents an alkyl group having 1 to 4 carbon atoms or a hydrogen atom. L is ¹ And L ² Each independently more preferably a single bond, -OR ^a2-1 -、-CH ₂ -、-CH ₂ CH ₂ -、-COOR ^a4-1 -, or-OCOR ^a6-1 -. Here, R ^a2-1 、R ^a4-1 、R ^a6 ^-1 Each independently represents a single bond、-CH ₂ -、-CH ₂ CH ₂ Any of (1) to (d). L is ¹ And L ² Further preferably a single bond, -O-, -CH ₂ CH ₂ -、-COO-、-COOCH ₂ CH ₂ -, or-OCO-.

B ¹ And B ² Each independently preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R ^a9 OR ^a10 -、-R ^a11 COOR ^a12 -、-R ^a13 OCOR ^a14 -, or-R ^a15 OC＝OOR ^a16 -. Here, R ^a9 ～R ^a16 Each independently represents a single bond or an alkylene group having 1 to 4 carbon atoms. B is ¹ And B ² Each independently more preferably a single bond, -OR ^a10-1 -、-CH ₂ -、-CH ₂ CH ₂ -、-COOR ^a12-1 -, or-OCOR ^a14-1 -. Here, R ^a10-1 、R ^a12-1 、R ^a14-1 Each independently represents a single bond, -CH ₂ -、-CH ₂ CH ₂ Any of (1) to (d). B is ¹ And B ² Further preferably a single bond, -O-, -CH ₂ CH ₂ -、-COO-、-COOCH ₂ CH ₂ -, -OCO-, or-OCOCH ₂ CH ₂ -。

From the viewpoint of exhibiting reverse wavelength dispersibility, k and l are preferably in the range of 2 ≦ k + l ≦ 6, more preferably k + l =4, and further preferably k =2 and l =2. If k =2 and l =2, a symmetrical structure is formed, and therefore, it is preferable.

As P ¹ Or P ² Examples of the polymerizable group include an epoxy group, a vinyl group, a vinyloxy group, a 1-chloroethenyl group, an isopropenyl group, a 4-vinylphenyl group, a (meth) acryloyl group, an epoxyethyl group, and an oxetanyl group. Among them, (meth) acryloyl, vinyl and vinyloxy are preferable, and (meth) acryloyl is more preferable.

Ar preferably has at least 1 selected from an aromatic hydrocarbon ring which may have a substituent, an aromatic heterocyclic ring which may have a substituent, and an electron-withdrawing group. Examples of the aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, and an anthracene ring, and a benzene ring and a naphthalene ring are preferable. Examples of the aromatic heterocyclic ring include a furan ring, a benzofuran ring, a pyrrole ring, an indole ring, a thiophene ring, a benzothiophene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a triazole ring, a triazine ring, a pyrroline ring, an imidazole ring, a pyrazole ring, a thiazole ring, a benzothiazole ring, a thienothiazole ring, an oxazole ring, a benzoxazole ring, and a phenanthroline ring. Among them, a thiazole ring, a benzothiazole ring, or a benzofuran ring is preferable, and a benzothiazole ring is more preferable. When Ar contains a nitrogen atom, the nitrogen atom preferably has pi electrons.

In the formula (X), the total number N of pi electrons of the group represented by Ar _π Usually 6 or more, preferably 8 or more, more preferably 10 or more, further preferably 14 or more, and particularly preferably 16 or more. Further, 36 or less, more preferably 32 or less, still more preferably 26 or less, 12391\\12426, particularly preferably 24 or less.

Examples of the aromatic group contained in Ar include the following groups.

[ solution 14]

In the formulae (Ar-1) to (Ar-23), the symbol denotes a linker, Z ⁰ 、Z ¹ And Z ² Each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, an alkylsulfinyl group having 1 to 12 carbon atoms, an alkylsulfonyl group having 1 to 12 carbon atoms, a carboxyl group, a fluoroalkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkylthio group having 1 to 12 carbon atoms, an N-alkylamino group having 1 to 12 carbon atoms, an N, N-dialkylamino group having 2 to 12 carbon atoms, an N-alkylsulfamoyl group having 1 to 12 carbon atoms or an N, N-dialkylsulfamoyl group having 2 to 12 carbon atoms. In addition, Z ⁰ 、Z ¹ And Z ² May contain a polymerizable group.

In the formulae (Ar-1) to (Ar-23), Q ¹ And Q ² Each independently represents-CR ^2’ R ^3’ -、-S-、-NH-、-NR ^2’ -, -CO-or-O-, R ^2’ And R ^3’ Each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

In formulae (Ar-1) to (Ar-23), J ¹ And J ² Each independently represents a carbon atom or a nitrogen atom.

In the formulae (Ar-1) to (Ar-23), Y ¹ 、Y ² And Y ³ Each independently represents an aromatic hydrocarbon group or an aromatic heterocyclic group which may be substituted.

In the formulae (Ar-1) to (Ar-23), W ¹ And W ² Each independently represents a hydrogen atom, a cyano group, a methyl group or a halogen atom, and m represents an integer of 0 to 6.

As Y ¹ 、Y ² And Y ³ The aromatic hydrocarbon group in (b) includes aromatic hydrocarbon groups having 6 to 20 carbon atoms such as a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, and a biphenyl group, preferably a phenyl group and a naphthyl group, and more preferably a phenyl group. Examples of the aromatic heterocyclic group include an aromatic heterocyclic group having 4 to 20 carbon atoms and containing at least 1 hetero atom such as a nitrogen atom, an oxygen atom, a sulfur atom and the like, such as furyl, pyrrolyl, thienyl, pyridyl, thiazolyl, benzothiazolyl and the like, and preferably furyl, thienyl, pyridyl, thiazolyl, benzothiazolyl and the like.

Y ¹ 、Y ² And Y ³ Each of which may be independently a polycyclic aromatic hydrocarbon group or a polycyclic aromatic heterocyclic group which may be substituted. The polycyclic aromatic hydrocarbon group means a fused polycyclic aromatic hydrocarbon group or a group derived from an aromatic ring assembly. The polycyclic aromatic heterocyclic group means a fused polycyclic aromatic heterocyclic group or a group derived from an aromatic ring assembly.

Z ⁰ 、Z ¹ And Z ² Each independently preferably represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, an alkoxy group having 1 to 12 carbon atoms, Z ⁰ More preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, Z ¹ And Z ² More preferably a hydrogen atom, fluorine atom, chlorine atom, methyl group or cyano group. In addition, Z ⁰ 、Z ¹ And Z ² May contain a polymerizable group.

Q ¹ And Q ² preferably-NH-, -S-, -NR ^2’ -、-O-，R ^2’ Preferably a hydrogen atom. Wherein the content of the first and second substances is controlled, particularly preferred is the group consisting of-O-, -NH-.

Among the formulae (Ar-1) to (Ar-23), the formulae (Ar-6) and (Ar-7) are preferred from the viewpoint of stability of the molecule.

In formulae (Ar-16) to (Ar-23), Y ¹ Nitrogen atom and Z which may be bonded thereto ⁰ Together form an aromatic heterocyclic group. Examples of the aromatic heterocyclic group include the aromatic heterocyclic groups described above as the aromatic heterocyclic group that may be contained in Ar, and examples thereof include a pyrrole ring, an imidazole ring, a pyrroline ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, an indole ring, a quinoline ring, an isoquinoline ring, a purine ring, a pyrrolidine ring, and the like. The aromatic heterocyclic group may have a substituent. In addition, Y ¹ Nitrogen atom and Z which may be bonded thereto ⁰ Together with the above-mentioned polycyclic aromatic hydrocarbon group or polycyclic aromatic heterocyclic group which may be substituted. Examples thereof include a benzofuran ring, a benzothiazole ring, and a benzoxazole ring.

The compound represented by the formula (X) can be produced, for example, according to the method described in japanese patent application laid-open No. 2010-31223.

In addition, as the polymerizable liquid crystal compound forming the horizontally aligned liquid crystal cured film in the present invention, for example, a compound containing a group represented by the following formula (Y) (hereinafter, also referred to as "polymerizable liquid crystal compound (Y)") can be used. The polymerizable liquid crystal compound (Y) generally tends to exhibit positive wavelength dispersibility.

P11-B11-E11-B12-A11-B13- (Y)

In the formula (Y), P11 represents a polymerizable group.

A11 represents a 2-valent alicyclic hydrocarbon group or a 2-valent aromatic hydrocarbon group.

B11 represents-O-, -S-) -CO-O-) -O-CO-, -O-CO-O-) -CO-NR ¹⁶ -、-NR ¹⁶ -CO-, -CS-or a single bond. R ¹⁶ Represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

B12 and B13 each independently represent-C ≡ C-) -CH = CH-, -CH ₂ -CH ₂ -、-O-、-S-、-C(＝O)-、-C(＝O)-O-、-O-C(＝O)-、-O-C(＝O)-O-、-CH＝N-、-N＝CH-、-N＝N-、-C(＝O)-NR ¹⁶ -、-NR ¹⁶ -C(＝O)-、-OCH ₂ -、-OCF ₂ -、-CH ₂ O-、-CF ₂ O-, -CH = CH-C (= O) -O-, -O-C (= O) -CH = CH-, -H, -C ≡ N, or a single bond.

E11 represents an alkanediyl group having 1 to 12 carbon atoms, wherein a hydrogen atom contained in the alkanediyl group may be substituted by an alkoxy group having 1 to 5 carbon atoms, and a hydrogen atom contained in the alkoxy group may be substituted by a halogen atom. In addition, a-CH group constituting the alkanediyl group ₂ -may be replaced by-O-or-CO-.]

The number of carbon atoms of the aromatic hydrocarbon group and the alicyclic hydrocarbon group in a11 is preferably in the range of 3 to 18, more preferably in the range of 5 to 12, and particularly preferably 5 or 6. The hydrogen atom contained in the 2-valent alicyclic hydrocarbon group and the 2-valent aromatic hydrocarbon group represented by a11 may be substituted by a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group or a nitro group, and the hydrogen atom contained in the alkyl group having 1 to 6 carbon atoms and the alkoxy group having 1 to 6 carbon atoms may be substituted by a fluorine atom. As A11, cyclohexane-1, 4-diyl and 1, 4-phenylene are preferable.

The E11 is preferably a linear alkanediyl group having 1 to 12 carbon atoms. -CH constituting the alkanediyl group ₂ -may be substituted by-O-.

Specific examples thereof include linear alkanediyl groups having 1 to 12 carbon atoms such as methylene, ethylene, propane-1, 3-diyl, butane-1, 4-diyl, pentane-1, 5-diyl, hexane-1, 6-diyl, heptane-1, 7-diyl, octane-1, 8-diyl, nonane-1, 9-diyl, decane-1, 10-diyl, undecane-1, 11-diyl and dodecane-1, 12-diyl; -CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -、-CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -and-CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -and the like.

As B12 and B13, each independently, it is preferably — O-, -S-, -C (= O) -O-, -O-C (= O) -O-, wherein-O-or-O-C (= O) -O-is more preferable.

The polymerizable group represented by P11 is preferably a radical polymerizable group or a cation polymerizable group in view of high polymerization reactivity, particularly high photopolymerization reactivity, and the polymerizable group is preferably a group represented by the following formulae (P-11) to (P-15) in view of not only easy handling but also easy production of the liquid crystal compound itself.

[ chemical 15]

[ in the formulae (P-11) to (P-15),

R ¹⁷ ～R ²¹ each independently represents an alkyl group having 1 to 6 carbon atoms or a hydrogen atom.]

Specific examples of the groups represented by the formulae (P-11) to (P-15) include the following formulae (P-16) to (P-20).

[ solution 16]

P11 is preferably a group represented by the formulae (P-14) to (P-20), more preferably a vinyl group, a P-stilbene group, an epoxy group or an oxetanyl group.

The group represented by P11-B11-is more preferably an acryloyloxy group or a methacryloyloxy group.

Examples of the polymerizable liquid crystal compound (Y) include compounds represented by formula (I), formula (II), formula (III), formula (IV), formula (V), and formula (VI).

P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-B16-E12-B17-P12 (I)

P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-F11 (II)

P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-E12-B17-P12 (III)

P11-B11-E11-B12-A11-B13-A12-B14-A13-F11 (IV)

P11-B11-E11-B12-A11-B13-A12-B14-E12-B17-P12 (V)

P11-B11-E11-B12-A11-B13-A12-F11 (VI)

(in the formula, wherein,

a11, B11 to B13 and P11 are the same as those in the above formula (A),

a12 to A14 are each independently synonymous with A11, B14 to B16 are each independently synonymous with B12, B17 is synonymous with B11, E12 is synonymous with E11, and P12 is synonymous with P11.

F11 represents a hydrogen atom, an alkyl group having 1 to 13 carbon atoms, an alkoxy group having 1 to 13 carbon atoms, a cyano group, a nitro group, a trifluoromethyl group, a dimethylamino group, a hydroxyl group, a hydroxymethyl group, a formyl group, a sulfo group (-SO) ₃ H) A carboxyl group, an alkoxycarbonyl group having 1 to 10 carbon atoms or a halogen atom, -CH which constitutes the alkyl group or the alkoxy group ₂ -may be substituted by-O-. )

Specific examples of the polymerizable liquid crystal compound (Y) include compounds having a polymerizable group among compounds described in "3.8.6 network (completely crosslinked type)" and "6.5.1 liquid crystal material b" in the liquid crystal display (edited by the liquid crystal display committee, manufactured by puisakusho, published in 12 years, 10 months, and 30 days), "and polymerizable liquid crystals described in japanese patent application laid-open nos. 2009-173893, 2010-31223, 2010-270108, 2011-6360, and 2011-207765.

The content of the polymerizable liquid crystal compound in the composition for forming a horizontally oriented liquid crystal cured film is, for example, 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, more preferably 85 to 98 parts by mass, and still more preferably 90 to 95 parts by mass, per 100 parts by mass of the solid content of the composition for forming a horizontally oriented liquid crystal cured film. When the content of the polymerizable liquid crystal compound is within the above range, it is advantageous from the viewpoint of alignment properties of the obtained liquid crystal cured film. When the composition for forming a horizontally aligned liquid crystal cured film contains 2 or more polymerizable liquid crystal compounds, the total content of all the polymerizable liquid crystal compounds contained in the composition for forming a horizontally aligned liquid crystal cured film is preferably within the above range.

The composition for forming a horizontally aligned liquid crystal cured film may contain a polymerization initiator for initiating a polymerization reaction of the polymerizable liquid crystal compound. The polymerization initiator may be suitably selected from polymerization initiators conventionally used in this field, and may be a thermal polymerization initiator or a photopolymerization initiator. From the viewpoint of being able to initiate polymerization under lower temperature conditions, a photopolymerization initiator is preferred. The same photopolymerization initiators as those exemplified above as photopolymerization initiators usable in the optically anisotropic film forming composition can be suitably used.

The composition for forming a horizontally aligned liquid crystal cured film is usually applied to a substrate or the like in a state of being dissolved in a solvent, and therefore preferably contains a solvent. The solvent is preferably a solvent capable of dissolving the polymerizable liquid crystal compound used, and is preferably a solvent inactive to the polymerization reaction of the polymerizable liquid crystal compound. The solvent may be the same as the solvent used in the optically anisotropic film forming composition exemplified above.

The composition for forming a horizontally aligned liquid crystal cured film may contain a photosensitizer, a leveling agent, an additive exemplified as an additive contained in the composition for forming an optically anisotropic film, and the like, as required. Examples of the photosensitizer and the leveling agent include the same photosensitizers and leveling agents as those exemplified above as photosensitizers and leveling agents that can be used in the composition for forming an optically anisotropic film.

The composition for forming a horizontally aligned liquid crystal cured film can be prepared, for example, by mixing and stirring a polymerizable liquid crystal compound and a polymerization initiator, a solvent, an additive, and the like used as necessary.

The horizontally aligned liquid crystal cured film can be obtained, for example, by applying a composition for forming a horizontally aligned liquid crystal cured film onto a substrate or an alignment film, drying the coating film, aligning the polymerizable liquid crystal compound in the composition for forming a horizontally aligned liquid crystal cured film in the horizontal direction, and then polymerizing the polymerizable liquid crystal compound by light irradiation or the like while maintaining the aligned state. As a method which can be employed for applying the composition for forming a horizontally aligned liquid crystal cured film, curing of a polymerizable liquid crystal compound by light irradiation, and the like, there can be mentioned a method exemplified as a method for forming an optically anisotropic film, and appropriate methods, conditions, and the like can be employed depending on components and the like constituting the horizontally aligned liquid crystal cured film.

The alignment film may be a photo-alignment film, in addition to the alignment film containing an alignment polymer as exemplified above as an alignment film that can be used in the production of the optically anisotropic film of the present invention. From the viewpoint of the accuracy of the alignment angle and the quality, a photo-alignment film is preferable as an alignment film for forming a horizontally aligned liquid crystal cured film.

The photo alignment film can be generally obtained by applying a composition containing a polymer or monomer having a photoreactive group and a solvent (hereinafter, also referred to as a "photo alignment film-forming composition") to a substrate, removing the solvent, and then irradiating polarized light (preferably polarized UV). The direction of the alignment regulating force can be arbitrarily controlled by selecting the polarization direction of the irradiated polarized light, and the photo alignment film is also advantageous from this point of view.

The photoreactive group refers to a group that generates liquid crystal alignment ability by light irradiation. Specifically, there may be mentioned groups which are involved in a photoreaction which is a source of liquid crystal aligning ability, such as orientation induction or isomerization reaction of molecules by light irradiation, dimerization reaction, photocrosslinking reaction, or photolysis reaction. Among them, a group participating in dimerization reaction or photocrosslinking reaction is preferable from the viewpoint of excellent orientation. As the photoreactive group, a group having an unsaturated bond, particularly a double bond, is preferable, and a group having at least 1 selected from a carbon-carbon double bond (C = C bond), a carbon-nitrogen double bond (C = N bond), a nitrogen-nitrogen double bond (N = N bond), and a carbon-oxygen double bond (C = O bond) is particularly preferable.

Examples of the photoreactive group having a C = C bond include a vinyl group, a polyene group, a stilbene group, a stilbazolium group, a chalcone group, a cinnamoyl group, and the like. Examples of the photoreactive group having a C = N bond include groups having a structure such as an aromatic schiff base and an aromatic hydrazone. Examples of the photoreactive group having an N = N bond include an azophenyl group, an azonaphthyl group, an aromatic heterocyclic azo group, a bisazo group, a formazan group (formazan group), and a group having an azoxybenzene structure. Examples of the photoreactive group having a C = O bond include a benzophenone group, a coumarin group, an anthraquinone group, and a maleimide group. These groups may have substituents such as alkyl groups, alkoxy groups, aryl groups, allyloxy groups, cyano groups, alkoxycarbonyl groups, hydroxyl groups, sulfonic acid groups, and haloalkyl groups.

Among them, a photoreactive group participating in a photodimerization reaction is preferable, and cinnamoyl group and chalcone group are preferable in terms of a small amount of polarized light irradiation necessary for photo-alignment, easy obtainment of a photo-alignment film having excellent thermal stability and temporal stability. As the polymer having a photoreactive group, a polymer having a cinnamoyl group which is a cinnamic acid structure at a terminal of a side chain of the polymer is particularly preferable.

By applying the composition for forming a photo-alignment film on a substrate, a photo-alignment inducing layer can be formed on the substrate. The solvent contained in the composition includes the same solvents as those exemplified above as solvents that can be used in the composition for forming an optically anisotropic film, and can be appropriately selected depending on the solubility of the polymer or monomer having a photoreactive group.

The content of the polymer or monomer having a photoreactive group in the composition for forming a photo alignment layer may be appropriately adjusted depending on the kind of the polymer or monomer and the thickness of the target photo alignment layer, but is preferably at least 0.2 mass%, and more preferably in the range of 0.3 to 10 mass% with respect to the mass of the composition for forming a photo alignment layer. The composition for forming a photo-alignment layer may include a polymer material such as polyvinyl alcohol or polyimide, and a photosensitizer in a range that does not significantly impair the characteristics of the photo-alignment layer.

The method of applying the composition for forming a photo-alignment film to a substrate may be the same as the method of applying the alignment polymer composition to a substrate. Examples of the method for removing the solvent from the applied composition for forming the photo-alignment film include a natural drying method, a forced air drying method, a heat drying method, and a reduced pressure drying method.

The method of irradiating polarized light may be a method of directly irradiating polarized UV to a coating film after removing a solvent from a composition for forming a photo-alignment film applied to a substrate, or a method of irradiating polarized light from the substrate side and transmitting the polarized light. In addition, the polarized light is particularly preferably substantially parallel light. The wavelength of the irradiated polarized light is preferably a wavelength of a wavelength region in which the photoreactive group of the polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet) having a wavelength of 250 to 400nm is particularly preferable. Examples of the light source used for the polarized light irradiation include a xenon lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, and an ultraviolet laser such as KrF and ArF, and more preferably a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, and a metal halide lamp. Among them, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, and a metal halide lamp are preferable because the emission intensity of ultraviolet rays having a wavelength of 313nm is large. Polarized UV can be irradiated by irradiating light from the light source after passing through an appropriate polarizing plate. As the polarizing plate, a polarizing prism such as a polarizing filter, a glan thomson prism, or a glan taylor prism, or a wire grid type polarizing plate can be used.

The thickness of the photo-alignment film for forming the horizontally aligned liquid crystal cured film is usually in the range of 10 to 10000nm, preferably in the range of 10 to 1000 nm.

In the laminate of the present invention, the thickness of the horizontally aligned retardation film (horizontally aligned liquid crystal cured film) may be appropriately selected depending on the display device to be used, and is preferably 0.1 to 10 μm, more preferably 0.5 to 5 μm, and still more preferably 1 to 3 μm from the viewpoint of making the film thin.

When the polarizing film and the horizontally oriented phase difference film are laminated, it is preferable that the slow axis (optical axis) of the horizontally oriented phase difference film and the absorption axis of the polarizing film are laminated so as to be substantially 45 °. The retardation film and the polarizing film are laminated so that the slow axis (optical axis) thereof and the absorption axis thereof are substantially 45 °, whereby the polarizing plate can function as a circularly polarizing plate. The angle is substantially 45 °, and is usually in the range of 45 ± 5 °.

The laminate of the present invention preferably further comprises a vertically oriented phase difference film on the side of the horizontally oriented phase difference film opposite to the polarizing film.

The vertically aligned retardation film that can constitute the laminate of the present invention is a retardation film that is aligned in a vertical direction with respect to the in-plane direction of the film, and may be, for example, a cured product of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound (hereinafter also referred to as "composition for forming a vertically aligned liquid crystal cured film"), a cured product obtained by curing a polymerizable liquid crystal compound in a state of being aligned in a vertical direction with respect to the plane of the retardation film (hereinafter also referred to as "vertically aligned liquid crystal cured film"), or the like.

The terms "vertically aligned retardation film" and "vertically aligned liquid crystal cured film" in the present specification are different from the optically anisotropic film of the present invention in that they do not satisfy the formulas (1) to (6) of the present application and the formulas (4) to (9) of the present application unless otherwise specified.

By combining a vertically aligned liquid crystal cured film with a laminate (circularly polarizing plate) including a polarizing film and a horizontally aligned retardation film, the vertically aligned liquid crystal cured film can function as an optical compensation film, and therefore, the color tone of oblique reflection in black display can be improved. The effect of the improvement (change) of the "oblique reflection color tone at the time of black display" is an effect of improving the oblique reflection color tone at the time of black display (that is, an effect of reducing light leakage when viewed from an oblique direction at the time of black display) when the optical anisotropic film and the horizontal alignment retardation film are applied in combination to the display device.

In the laminate of the present invention, the vertically aligned liquid crystal cured film preferably satisfies the following formulae (18) and (19).

-100nm≤RthC(550)≤-20nm (18)

RthC(450)/RthC(550)＞1.00 (19)

In the formulae (18) and (19), rth (λ) represents a retardation value in the thickness direction of the vertically aligned retardation film at a wavelength λ nm. The value of RthC (550) and the value of RthC (450)/RthC (550) indicate the alignment state of the polymerizable liquid crystal compound in the vertically aligned liquid crystal cured film, and are one index of the degree of the oblique optical compensation effect in the case of black display.

The retardation value RthC (550) in the film thickness direction of the vertically aligned liquid crystal cured film is more preferably-90 nm or more, still more preferably-80 nm or more, still more preferably-40 nm or less, and still more preferably-50 nm or less, from the viewpoint of further improving the color tone of the oblique reflection in black display.

The retardation value RthC (λ) in the film thickness direction of the vertically aligned liquid crystal cured film can be adjusted by the thickness dC of the vertically aligned liquid crystal cured film. Since the in-plane phase difference value is determined by:

RthC(λ)＝((nxC(λ)+nyC(λ))/2-nzC(λ))×dC

(here, nxC (λ) represents an in-plane main refractive index of the vertically aligned liquid crystal cured film at a wavelength λ nm, nyC (λ) represents a refractive index in a direction orthogonal to nxC (λ) in the plane at the wavelength λ nm, nzC (λ) represents a refractive index in a thickness direction of the vertically aligned liquid crystal cured film at the wavelength λ nm, and in the case where nxC (λ) = nyC (λ), nxC (λ) may be a refractive index in an arbitrary direction in the film surface, and dC represents a film thickness of the vertically aligned liquid crystal cured film.)

Therefore, in order to obtain the desired phase difference value RthC (λ) in the film thickness direction, the three-dimensional refractive index and the film thickness dC may be adjusted. The three-dimensional refractive index depends on the molecular structure and alignment state of the polymerizable liquid crystal compound.

An example of the laminate of the present invention is a laminate in which the optically anisotropic film of the present invention is bonded to the horizontally oriented retardation film side of a circularly polarizing plate in which a polarizing film and a horizontally oriented retardation film are bonded to each other. When the laminate is incorporated into an organic EL display device, the front tone and the oblique tone in white display can be improved, and the effect of improving the oblique tone in black display can be exhibited.

Another example of the laminate of the present invention includes a laminate comprising the optically anisotropic film of the present invention, a polarizing film, a horizontally oriented retardation film, and a vertically oriented retardation film in this order. The laminate of the present invention has a high effect of improving the front color tone in white display and a high effect of improving the oblique color tone in black display, and is excellent in the effect of improving the oblique color tone in black display.

Examples of the polymerizable liquid crystal compound forming the vertically aligned retardation film constituting the laminate of the present invention include the polymerizable liquid crystal compound (X) and the polymerizable liquid crystal compound (Y) exemplified above as the polymerizable liquid crystal compound capable of forming the horizontally aligned retardation film.

The vertically aligned retardation film can be obtained, for example, by applying a composition for forming a vertically aligned liquid crystal cured film, which contains a polymerizable liquid crystal compound, an additive such as a polymerization initiator and a leveling agent, which are used as needed, and a solvent, onto a substrate with or without an alignment film interposed therebetween, drying the coating film, aligning the polymerizable liquid crystal compound in the composition for forming a vertically aligned liquid crystal cured film in the vertical direction, and then polymerizing the polymerizable liquid crystal compound by light irradiation or the like while maintaining the aligned state. Examples of the additives such as a polymerization initiator and a leveling agent, and the solvent that can be used include those similar to the examples given above as the ones that can be used in the production of the optically anisotropic film of the present invention. Examples of the alignment film include an alignment film containing a vertical alignment-promoting compound, an alignment film containing an alignment polymer, and the like, which are exemplified above as alignment films that can be used in the production of the optically anisotropic film of the present invention. Further, as a method which can be employed for applying the composition for forming a vertically aligned liquid crystal cured film, curing of a polymerizable liquid crystal compound by light irradiation, or the like, there can be mentioned a method exemplified as a method for forming an optically anisotropic film, and appropriate methods, conditions, and the like can be employed depending on components constituting the vertically aligned liquid crystal cured film.

In the laminate of the present invention, the thickness of the vertically aligned retardation film (vertically aligned liquid crystal cured film) can be appropriately selected depending on the display device to be used, and is preferably 0.1 to 10 μm, more preferably 0.5 to 5 μm, and still more preferably 1 to 3 μm from the viewpoint of making the film thin.

In the laminate of the present invention, the optically anisotropic film, the polarizing film, the horizontally oriented phase difference film, and the vertically oriented phase difference film may be bonded to each other through an adhesive layer. The adhesive used for forming the adhesive layer is not particularly limited, and any adhesive known in the art can be suitably selected and used. In addition, for example, by forming a vertical alignment retardation film containing the composition for forming a vertically aligned liquid crystal cured film on a horizontal alignment retardation film with or without an alignment film having a vertical alignment regulating force interposed therebetween, it is easy to reduce the thickness of a laminate.

The laminate of the present invention may have a structure provided in a conventional general circularly polarizing plate, or a polarizing film and a retardation film. Examples of such a structure include an adhesive layer (sheet) for bonding a circularly polarizing plate to a display device such as an organic EL, and a protective film used for the purpose of protecting the surfaces of a polarizing film and a retardation film from damage and contamination.

The optically anisotropic film and the laminate of the present invention can be used for various display devices.

The display device is a device having a display element, and includes a light-emitting element or a light-emitting device as a light-emitting source. Examples of the display device include a liquid crystal display device, an organic Electroluminescence (EL) display device, an inorganic Electroluminescence (EL) display device, a touch panel display device, an electron emission display device (e.g., an electric field emission display device (FED), a surface field emission display device (SED)), electronic paper (a display device using electronic ink, an electrophoretic element, a plasma display device, a projection display device (e.g., a Grating Light Valve (GLV) display device, a display device having a Digital Micromirror Device (DMD)), and a piezoelectric ceramic display, etc.).

Examples

The present invention will be described in more detail with reference to examples. In the examples, "%" and "part(s)" are% by mass and part(s) by mass, respectively, unless otherwise specified.

1. Production of a horizontally oriented retardation film

(1) Preparation of composition for Forming horizontally oriented film

A composition for forming a horizontally aligned film was obtained by mixing 5 parts (weight average molecular weight: 30000) of a photo-alignment material having the following structure and 95 parts of cyclopentanone (solvent) as components, and stirring the resulting mixture at 80 ℃ for 1 hour.

[ solution 17]

(2) Preparation of polymerizable liquid Crystal Compound

A polymerizable liquid crystal compound (X1) and a polymerizable liquid crystal compound (X2) each having the following molecular structure were prepared. The polymerizable liquid crystal compound (X1) is produced according to the method described in japanese patent application laid-open No. 2010-31223. The polymerizable liquid crystal compound (X2) is produced by the method described in jp 2009-173893 a.

Polymerizable liquid Crystal Compound (X1)

[ solution 18]

Polymerizable liquid Crystal Compound (X2)

[ solution 19]

1mg of the polymerizable liquid crystal compound (X1) was dissolved in 50mL of tetrahydrofuran to obtain a solution. The obtained solution was charged into a measuring cell having an optical path length of 1cm as a measuring sample, and the measuring cell was set in an ultraviolet-visible spectrophotometer ("UV-2450" manufactured by Shimadzu corporation) to measure an absorption spectrum. The wavelength at which the maximum absorbance is obtained is read from the obtained absorption spectrum, and as a result, the maximum absorption wavelength λ max in the wavelength range of 300 to 400nm is 350nm.

(3) Preparation of polymerizable liquid Crystal composition for Forming horizontally aligned retardation film

Mixing a polymerizable liquid crystal compound (X1) and a polymerizable liquid crystal compound (X2) at a mass ratio of 90:10 to obtain a mixture. To 100 parts by mass of the obtained mixture, 0.1 part by mass of a leveling agent "BYK-361N" (BM Chemie) and 6 parts by mass of 2-dimethylamino-2-benzyl-1- (4-morpholinophenyl) butan-1-one (Irgacure (registered trademark) 369 (Irg 369, manufactured by BASF Japan) as a photopolymerization initiator were added. Further, N-methyl-2-pyrrolidone (NMP) was added so that the solid content concentration was 13%. The mixture was stirred at 80 ℃ for 1 hour to obtain a polymerizable liquid crystal composition for forming a horizontally aligned retardation film.

(4) Production of a horizontally oriented retardation film (horizontally oriented liquid Crystal cured film)

After performing corona treatment on a COP film (ZF-14-50) manufactured by Nippon ZEON Co., ltd., the composition for forming a horizontally oriented film was applied by a bar coater, dried at 80 ℃ for 1 minute, and irradiated with polarized UV light (SPOT CURE SP-9 manufactured by USHIO Motor Co., ltd.) at a cumulative light amount at a wavelength of 313nm of 100mJ/cm ² Polarized UV exposure was performed to obtain a horizontally oriented film.

Next, the bar coating machine was used to take the bar horizontallyThe film was coated with the polymerizable liquid crystal composition for forming a horizontally aligned retardation film, heated at 120 ℃ for 60 seconds, and then irradiated with ultraviolet light (cumulative light amount at wavelength of 365nm under nitrogen atmosphere: 500 mJ/cm) from the surface coated with the polymerizable liquid crystal composition for forming a horizontally aligned retardation film using a high pressure mercury lamp (UNICURE VB-15201BY-A, manufactured BY USHIO Motor Co., ltd.) ² ) Thereby, a horizontally aligned retardation film (horizontally aligned liquid crystal cured film) was formed.

After confirming that there was no phase difference in the COP film, re (450) and Re (550) were measured using KOBRA-WPR manufactured by prince instruments, and α = Re (450)/Re (550) was calculated. The resulting horizontally aligned retardation film had an α of 0.92.

2. Production of polarizing film

A polyvinyl alcohol film having a thickness of 75 μm and an average degree of polymerization of about 2400 and a degree of saponification of 99.9 mol% or more was immersed in pure water at 30 ℃ and then immersed in an aqueous solution having a mass ratio of iodine/potassium iodide/water of 0.02/2/100 at 30 ℃ to carry out iodine dyeing (iodine dyeing step). The polyvinyl alcohol film subjected to the iodine dyeing step was immersed in an aqueous solution having a potassium iodide/boric acid/water mass ratio of 12/5/100 at 56.5 ℃ to be subjected to boric acid treatment (boric acid treatment step). The polyvinyl alcohol film subjected to the boric acid treatment step was washed with pure water at 8 ℃ and then dried at 65 ℃ to obtain a polarizing plate (thickness after stretching 27 μm) in which iodine was adsorbed to polyvinyl alcohol and oriented. In this case, stretching is performed in the iodine dyeing step and the boric acid treatment step. The total draw ratio in this drawing was 5.3 times. The obtained polarizing plate and a saponified triacetyl cellulose film (KC 4UYTAC40 μm manufactured by Konica Minolta) were bonded to each other with a nip roll via an aqueous adhesive. The resulting laminate was dried at 60 ℃ for 2 minutes while maintaining the tension of 430N/m, to obtain a polarizing film having a triacetyl cellulose film as a protective film on one side.

The aqueous adhesive was prepared by adding 3 parts by mass of carboxyl-modified polyvinyl alcohol (Kuraray Poval KL318, manufactured by Kuraray) and 1.5 parts by mass of water-soluble polyamide epoxy Resin (Sumirez Resin 650, manufactured by Sumika ChemteX, an aqueous solution having a solid content concentration of 30%) to 100 parts by mass of water.

3. Production of a vertical alignment retardation film

(1) Preparation of composition for Forming vertically aligned film

A composition for forming a vertically aligned film was prepared by mixing 0.5 parts by mass of polyimide ("SUNEVER SE-610", manufactured by Nissan chemical Co., ltd.), 72.3 parts by mass of N-methyl-2-pyrrolidone, 18.1 parts by mass of 2-butoxyethanol, 9.1 parts by mass of ethylcyclohexane, and 0.01 part by mass of DPHA (manufactured by Nissan chemical Co., ltd.).

(2) Preparation of polymerizable liquid Crystal composition for Forming vertical alignment liquid Crystal cured film

A liquid crystal compound LC242 represented by the following formula (LC 242): paliocoloorlLC 242 (registered trademark of BASF corporation) was added in an amount of 100 parts by mass, a leveling agent (F-556, manufactured by DIC corporation) was added in an amount of 0.1 part by mass, and a polymerization initiator Irg369 3 parts by mass, and cyclopentanone was added so that the solid content concentration became 13 parts by mass. These were mixed to obtain a polymerizable liquid crystal composition for forming a vertically aligned liquid crystal cured film.

Liquid crystal compound LC242: paliocoloorlLC 242 (BASF company registered trademark)

[ solution 20]

(3) Production of vertical alignment retardation film (vertical alignment liquid Crystal cured film)

A COP film (ZF-14-23, manufactured by ZEON K.K., japan) was used as a substrate, and this COP film was subjected to corona treatment. The corona-treated COP film was coated with the composition for forming a vertically aligned film using a bar coater to form a coating film. The coating film was dried at 80 ℃ for 1 minute to obtain a vertically oriented film. The thickness of the obtained vertical alignment film was measured by an ellipsometer and found to be 0.2. Mu.m. Next, the polymerizable liquid crystal composition for forming a vertically aligned liquid crystal cured film was applied to the prepared vertically aligned film to form a coating film. The coating film was dried at 80 ℃ for 1 minute, and then the resultant was irradiated with a high-pressure mercury lamp (UNICURE VB-15201BY-A manufactured BY USHIO MOTOR CO., LTD.) under a nitrogen atmosphere and at a wavelength of lightCumulative light quantity at 365nm of 500mJ/cm ² Irradiating the dried coating film with ultraviolet rays under the conditions of (1) to form a vertically aligned retardation film (vertically aligned liquid crystal cured film).

4. Component used in composition for forming optically anisotropic film

(1) Polymerizable liquid crystal compound

The polymerizable liquid crystal compounds (A1) and (A2) were synthesized according to the method described in Lub et al, recl.Trav.Chim.Pays-Bas, 115, 321-328 (1996).

[ solution 21]

(2) Dichroic dye

Dichroic dye a (Cyan 1: cyan dye): maximum absorption wavelength 592nm (measured in chloroform solution)

[ chemical 22]

Dichroic dye B (Yellow 1: yellow dye): maximum absorption wavelength 445nm (measured in chloroform solution)

[ solution 23]

Dichroic pigment C (Magenta 1: magenta): maximum absorption wavelength 546nm (measured in chloroform solution)

[ solution 24]

Dichroic dye D (Cyan 2: cyan dye): maximum absorption wavelength 600nm (measured in chloroform solution)

[ solution 25]

Dichroic pigment E (Cyan 3: cyan pigment): maximum absorption wavelength 600nm (measured in chloroform solution)

[ chemical 26]

Dichroic dye F (Yellow 2: yellow dye): maximum absorption wavelength 386nm (measured in chloroform solution)

[ solution 27]

Dichroic pigment G (Magenta 2: magenta): maximum absorption wavelength 489nm (measured in chloroform solution)

[ solution 28]

Example 1

(1) Production of optically anisotropic film

(i) Preparation of composition for forming optically anisotropic film

The ratio of the polymerizable liquid crystal compound (A1) to the polymerizable liquid crystal compound (A2) in a mass ratio of 90: 100 parts by mass of a mixture of polymerizable liquid crystal compounds obtained by mixing 10 parts by mass of a leveling agent "F-556" (manufactured by DIC Co., ltd.) 0.25 part by mass, a dichroic dye A1.2 part by mass, a dichroic dye C1.7 part by mass, and 2-dimethylamino-2-benzyl-1- (4-morpholinophenyl) butan-1-one (Irgacure (registered trademark) 369 (Irg 369) manufactured by BASF Japan K.K.) 6 parts by mass as a photopolymerization initiator were added. Further, o-xylene was added so that the solid content concentration was 25%. This mixture was stirred at 80 ℃ for 30 minutes, thereby obtaining an optically anisotropic film-forming composition.

(ii) Preparation of composition for Forming vertical alignment film

A silane coupling agent "KBE-9103" (manufactured by shin-Etsu chemical Co., ltd.) was dissolved in a mixture of ethanol and water in a ratio of 9:1 (mass ratio) to obtain a composition for forming a vertically aligned film having a solid content of 1%.

(iii) Production of optically anisotropic film

After performing corona treatment on a COP film (ZF-14-50) manufactured by Nippon ZEON Co., ltd, a composition for forming a vertically aligned film was applied by a bar coater and dried at 120 ℃ for 1 minute, thereby obtaining a vertically aligned film.

Next, the resulting vertically aligned film was coated with the optically anisotropic film-forming composition BY a bar coater, dried at 120 ℃ for 1 minute, and then irradiated with ultraviolet light (cumulative amount of light at 365nm in nitrogen atmosphere: 500 mJ/cm) from the side coated with the optically anisotropic film-forming composition BY a high pressure mercury lamp (UNICURE VB-15201BY-A, manufactured BY USHIO Motor Co., ltd.) ² ) Thereby forming an optically anisotropic film. The film thickness of the obtained optically anisotropic film was measured by an interferometric film thickness meter, and as a result, it was 0.9 μm.

(2) Measurement of absorbance of optically anisotropic film

The coated surface of the obtained optically anisotropic film was bonded to a glass 4X 4cm X having a thickness of 0.7mm via a 25 μm pressure-sensitive adhesive (manufactured by LINTEC). The resultant was placed in an ultraviolet-visible spectrophotometer ("UV-2450" manufactured by Shimadzu corporation), and the absorbance was measured to calculate Ax λ and Ax λ (z = 50). The results are shown in table 2.

The x-axis refers to an arbitrary direction in the plane of the optically anisotropic film, the y-axis refers to a direction perpendicular to the x-axis in the film plane, and the z-axis refers to the thickness direction of the optically anisotropic film. Ax λ and Ax λ (z = 50) are both absorbances at a wavelength λ (450 nm, 550nm, 650 nm) of the optically anisotropic film, ax λ represents an absorbance of linearly polarized light vibrating in the x-axis direction, and Ax λ (z = 50) represents an absorbance of linearly polarized light vibrating in the x-axis direction when the film is rotated by 50 ° about the y-axis as a rotation axis.

In addition, when the absorbance was measured, the sample was set in an ultraviolet-visible spectrophotometer ("UV-2450" manufactured by Shimadzu corporation) and corrected so that the absorbance at 800nm became zero, and Ax λ was measured. Ax λ (z = 50) was also measured by similarly mounting and tilting the sample, and then correcting the sample so that the absorbance at 800nm becomes zero (z = 50).

(3) Evaluation of orientation of optically anisotropic film

The coated surface of the obtained optically anisotropic film was bonded to a glass 4X 4cm X having a thickness of 0.7mm via a 25 μm pressure-sensitive adhesive (manufactured by LINTEC). The bonded optically anisotropic film was observed with a polarizing microscope, and defects due to defective alignment were evaluated according to the following criteria. The results are shown in table 2.

< evaluation Standard >

A: in the observation of magnification of 200 times, defects were not substantially observed.

B: in the observation of magnification of 200 times, defects were slightly observed.

C: in the observation of 200 times magnification, defects were observed.

(4) Production of circularly polarizing plate laminate

(i) Production of a laminate of a horizontally oriented retardation film and an optically anisotropic film

The coated surfaces (liquid crystal layer side) of the horizontally oriented retardation film and the optically anisotropic film obtained by the above-described production methods were subjected to corona treatment, and then the coated surfaces (liquid crystal layer side) were bonded to each other with an adhesive (25 μm, pressure sensitive adhesive manufactured by linetec corporation) interposed therebetween to produce a laminate of the horizontally oriented retardation film and the optically anisotropic film.

(ii) Production of circularly polarizing plate laminate

Then, the surface of the substrate (COP film) on the side of the horizontally oriented phase difference film of the laminate thus obtained was subjected to corona treatment, and then was bonded to a polarizing film via an adhesive (25 μm pressure-sensitive adhesive manufactured by LINTEC corporation) so that the angle between the absorption axis of the polarizing film and the slow axis of the horizontally oriented phase difference film became 45 °, to produce a circularly polarizing plate laminate comprising the polarizing film, the horizontally oriented phase difference film, and the optically anisotropic film in this order.

(5) Evaluation of optical Properties

(i) Evaluation of color tone in Black display

< Panel for evaluation >

Oblique yellow panel: flexPai, royole Inc

Oblique blue panel: galaxy S8 manufactured by SAMSUNG

< confirmation of front reflection color tone and oblique reflection color tone >

The front glass and the polarizing plate were removed from "FlexPai" manufactured by ROYOLE corporation, and the display device was taken out. Then, the circularly polarizing plate laminate produced by the above-described method was bonded to the display device with an adhesive (pressure-sensitive adhesive 25 μm manufactured by linec), and the front reflection color tone and the oblique reflection color tone were confirmed in a state where the power supply of the display device was turned OFF (in the case of black display), and evaluated in accordance with the following criteria. The results are shown in table 3.

The front reflection color tone is a color tone obtained by visually observing the sample at a distance of 50cm from the front and then confirming the color tone, and the oblique reflection color tone is a color tone obtained by visually observing the sample at a distance of 30cm from the elevation angle of 50 ° and the azimuth angle of 0 to 360 °.

< evaluation Standard >

A: the color tone was visually observed under the condition of being aligned with the glossy black drawing paper at 1m directly below the 40W three-wavelength lamp, and the color tone (Japanese: color tone) was not substantially perceived.

B: at 1.5m directly below the 40W three-wavelength lamp, a color odor was slightly perceived when confirmed with the naked eye alone, the color odor varied depending on the azimuth angle, and a bluish black color and a reddish black color were slightly observed.

C: at 1.5m directly below the 40W three-wavelength lamp, when visually confirmed alone, the color and taste were perceived, and the color and taste differed depending on the azimuth angle, and bluish and reddish black were observed.

(ii) Evaluation of color tone in white display

After the evaluation in black display, the same sample was used, the power of the display device was turned ON, the setting of the blue light rejection function, the color balance change, and other changes to the screen display color were all turned OFF after the brightness was maximized, and the front tone and the diagonal tone in white display were confirmed in a state where a white screen was displayed (a state where the color code # FFFFFF of HTML was displayed), and the evaluation was performed in accordance with the following criteria. The results are shown in table 3.

The front color tone is a color tone when visually observed at a distance of 30cm from the front surface of the sample, and the oblique color tone is a color tone visually observed from the direction of an elevation angle of 50 ° and an azimuth angle of 0 to 360 ° in a state of being separated by 30cm from the sample.

< evaluation Standard >

A: white display is performed in a dark room, and the color tone is visually confirmed without feeling the color or taste

B: white display was performed in a dark room, and the color tone was confirmed with the naked eye, and the color and the taste were not substantially perceived.

C: the white display was performed in a dark room, and the color tone was visually confirmed, and the color and taste were perceived.

D: white display was performed in a dark room, and the color tone was visually confirmed, so that the color and taste were strongly perceived.

Example 2

As the optically anisotropic film, an optically anisotropic film produced by the same procedure as in example 1 was used. The coated surface (liquid crystal layer side) of the horizontally oriented retardation film was subjected to corona treatment, and then was bonded to a polarizing film via an adhesive (25 μm, pressure-sensitive adhesive manufactured by LINTEC corporation) so that the angle formed by the absorption axis of the polarizing film and the slow axis of the horizontally oriented retardation film became 45 °, to prepare a laminate. Then, the coated surface (liquid crystal layer side) of the optically anisotropic film was subjected to corona treatment, and then was laminated to the polarizing film side of the laminate via an adhesive (pressure-sensitive adhesive 25 μm manufactured by LINTEC corporation), thereby producing a circularly polarizing plate laminate comprising an optically anisotropic film, a polarizing film, and a horizontally oriented retardation film in this order.

The optical properties of the circularly polarizing plate laminate were evaluated by the same procedure as in example 1. The results are shown in tables 2 and 3.

Example 3

As the optically anisotropic film, an optically anisotropic film produced by the same procedure as in example 1 was used. After the application surface (liquid crystal layer side) of the horizontally oriented retardation film was subjected to corona treatment, the film was laminated to a polarizing film via an adhesive (pressure-sensitive adhesive 25 μm manufactured by LINTEC corporation) so that the angle formed by the absorption axis of the polarizing film and the slow axis of the horizontally oriented retardation film became 45 °, to prepare a laminate of the polarizing film and the horizontally oriented retardation film. Then, the substrate side of the horizontally oriented retardation film and the application surface (liquid crystal layer side) of the vertically oriented retardation film of the laminate thus obtained were subjected to corona treatment, and then they were laminated with each other via an adhesive (25 μm pressure sensitive adhesive manufactured by LINTEC corporation) to produce a new laminate comprising a polarizing film, a horizontally oriented retardation film, and a vertically oriented retardation film in this order. Then, the coated surface (liquid crystal layer side) of the optically anisotropic film was subjected to corona treatment, and then the laminate was laminated with an adhesive (pressure-sensitive adhesive 25 μm manufactured by LINTEC corporation) to produce a circularly polarizing plate laminate comprising an optically anisotropic film, a polarizing film, a horizontally oriented retardation film, and a vertically oriented retardation film in this order.

Examples 4 and 5

An optically anisotropic film was produced by the same procedure as in example 1, except that the amounts of the dichroic dye a and the dichroic dye C were changed to the amounts shown in table 1. A circularly polarizing plate laminate comprising an optically anisotropic film, a polarizing film, a horizontally oriented retardation film, and a vertically oriented retardation film in this order was produced by the same procedure as in example 3, except that the optically anisotropic film thus obtained was used.

Examples 6 and 7

An optically anisotropic film was produced by the same procedure as in example 1, except that the amounts of dichroic dyes a and C to be blended were changed to the amounts shown in table 1, and the film thickness was changed to the thickness shown in table 1. A circularly polarizing plate laminate comprising an optically anisotropic film, a polarizing film, a horizontally oriented retardation film, and a vertically oriented retardation film in this order was produced by the same procedure as in example 3, except that the optically anisotropic film thus obtained was used.

Comparative example 1

(1) Production of optically Anisotropic film

(i) Preparation of composition for Forming optically Anisotropic film

The mass ratio of the polymerizable liquid crystal compound (A1) to the polymerizable liquid crystal compound (A2) is 90: 100 parts by mass of a mixture of polymerizable liquid crystal compounds obtained by mixing 10 parts by mass of a leveling agent "F-556" (manufactured by DIC) 0.25 part by mass, a dichroic dye A3.0 part by mass, and a photopolymerization initiator 2-dimethylamino-2-benzyl-1- (4-morpholinophenyl) butan-1-one (Irgacure (registered trademark) 369 (Irg 369, manufactured by BASF Japan K.K.) 6 parts by mass were added. Further, o-xylene was added so that the solid content concentration was 25%. The mixture was stirred at 80 ℃ for 30 minutes, thereby obtaining an optically anisotropic film-forming composition.

(ii) Preparation of composition for Forming vertically aligned film

A silane coupling agent "KBE-9103" (manufactured by shin-Etsu chemical Co., ltd.) was dissolved in a mixture of ethanol and water in a ratio of 9:1 (mass ratio) to obtain a vertically aligned film-forming composition having a solid content of 1%.

(iii) Production of optically anisotropic film

Next, the obtained vertically aligned film was coated with the composition for forming an optically anisotropic film BY using a bar coater, dried at 120 ℃ for 1 minute, and then irradiated with ultraviolet rays (cumulative light amount at 365nm wavelength in nitrogen atmosphere: 500 mJ/cm) from the surface side coated with the composition for forming an optically anisotropic film BY using a high pressure mercury lamp (UNICURE VB-15201BY-A, manufactured BY USHIO Motor Co., ltd.) ² ) Thereby forming an optically anisotropic film. The film thickness of the obtained optically anisotropic film was measured by an interferometric film thickness meter, and as a result, it was 0.6 μm.

The absorbance of the optically anisotropic film was measured by the same procedure as in example. The results are shown in table 2.

(2) Production of circularly polarizing plate laminate

A circularly polarizing plate laminate comprising a polarizing film, a horizontally oriented retardation film, and an optically anisotropic film in this order was produced by the same procedure as in example 1, except that the obtained optically anisotropic film was used as the optically anisotropic film.

The optical properties of the circularly polarizing plate laminate were evaluated by the same procedure as in example 1. The results are shown in table 3.

Comparative example 2

A circularly polarizing plate laminate comprising an optically anisotropic film, a polarizing film, and a horizontally oriented phase difference film in this order was produced by the same procedure as in example 2, except that the optically anisotropic film produced by the same procedure as in comparative example 1 was used as the optically anisotropic film.

Comparative example 3

A circularly polarizing plate laminate comprising an optically anisotropic film, a polarizing film, a horizontally oriented retardation film, and a vertically oriented retardation film in this order was produced by the same procedure as in example 3, except that the optically anisotropic film produced by the same procedure as in comparative example 1 was used as the optically anisotropic film.

Comparative example 4

An optically anisotropic film was produced by the same procedure as in example 1, except that the combination of dichroic dyes a and C was replaced with the combination of dichroic dyes a and B, and the blending amount was set to the amount described in table 1. A circularly polarizing plate laminate comprising an optically anisotropic film, a polarizing film, a horizontally oriented retardation film, and a vertically oriented retardation film in this order was produced by the same procedure as in example 3, except that the obtained optically anisotropic film was used.

Example 8

An optically anisotropic film was produced by the same procedure as in example 3, except that the dichroic dye D (Cyan 2) was used in place of the dichroic dye a (Cyan 1). A circularly polarizing plate laminate comprising an optically anisotropic film, a polarizing film, a horizontally oriented retardation film, and a vertically oriented retardation film in this order was produced by the same procedure as in example 3, except that the optically anisotropic film thus obtained was used.

Example 9

An optically anisotropic film was produced by the same procedure as in example 3, except that a dichroic dye E (Cyan 3) was used in place of the dichroic dye a (Cyan 1). A circularly polarizing plate laminate comprising an optically anisotropic film, a polarizing film, a horizontally oriented retardation film, and a vertically oriented retardation film in this order was produced by the same procedure as in example 3, except that the optically anisotropic film thus obtained was used.

The optical properties of the circularly polarizing plate laminate were evaluated in the same manner as in example 1. The results are shown in tables 2 and 3.

Example 10

In addition to the dichroic dye a (Cyan 1), a dichroic dye D (Cyan 2) and a dichroic dye E (Cyan 3) were used in a mass ratio D: e =1.0:1.4 an optically anisotropic film was produced by the same procedure as in example 3 except for using the mixture. A circularly polarizing plate laminate comprising an optically anisotropic film, a polarizing film, a horizontally oriented retardation film, and a vertically oriented retardation film in this order was produced by the same procedure as in example 3, except that the optically anisotropic film thus obtained was used.

Example 11

An optically anisotropic film was produced by the same procedure as in example 3, except that the dichroic dye G (Magenta 2) was used instead of the dichroic dye C (Magenta 1). A circularly polarizing plate laminate comprising an optically anisotropic film, a polarizing film, a horizontally oriented retardation film, and a vertically oriented retardation film in this order was produced by the same procedure as in example 3, except that the optically anisotropic film thus obtained was used.

Example 12

An optically anisotropic film was produced by the same procedure as in example 10, except that the dichroic dye G (Magenta 2) was used instead of the dichroic dye C (Magenta 1). A circularly polarizing plate laminate comprising an optically anisotropic film, a polarizing film, a horizontally oriented retardation film, and a vertically oriented retardation film in this order was produced by the same procedure as in example 3, except that the optically anisotropic film thus obtained was used.

Example 13

An optically anisotropic film was produced by the same procedure as in example 3, except that the dichroic dye B (Yellow 1) was used instead of the dichroic dye a (Cyan 1), and the dichroic dye G (Magenta 2) was used instead of the dichroic dye C (Magenta 1). A circularly polarizing plate laminate comprising an optically anisotropic film, a polarizing film, a horizontally oriented retardation film, and a vertically oriented retardation film in this order was produced by the same procedure as in example 3, except that the optically anisotropic film thus obtained was used.

The optical properties of the circularly polarizing plate laminate were evaluated in the same manner as in example 1. Note that, an oblique blue panel was used: galaxy S8 manufactured by SAMSUNG corporation was used as a panel for evaluation. The results of color tones are shown in tables 2 and 3.

Example 14

An optically anisotropic film was produced by the same procedure as in example 13, except that a dichroic dye F (Yellow 2) was used instead of the dichroic dye B (Yellow 1). A circularly polarizing plate laminate comprising an optically anisotropic film, a polarizing film, a horizontally oriented retardation film, and a vertically oriented retardation film in this order was produced by the same procedure as in example 3, except that the optically anisotropic film thus obtained was used.

The optical properties of the circularly polarizing plate laminate were evaluated by the same procedure as in example 13. The results of color tones are shown in tables 2 and 3.

[ TABLE 1]

[ TABLE 2]

[ TABLE 3]

Claims

1. An optically anisotropic film which is a cured film of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound and at least 2 kinds of dichroic dyes, is obtained by curing the polymerizable liquid crystal compound and the at least 2 kinds of dichroic dyes in a state of being molecularly oriented in a direction perpendicular to a film plane, and satisfies the following formulas (1) to (6) or formulas (4) to (9):

0.001≤Ax450(z＝50)≤0.100 (1)

0.070≤Ax550(z＝50)≤1.000 (2)

0.070≤Ax650(z＝50)≤1.000 (3)

0.001≤Ax450≤0.050 (4)

0.001≤Ax550≤0.050 (5)

0.001≤Ax650≤0.050 (6)

0.050≤Ax450(z＝50)≤1.000 (7)

0.070≤Ax550(z＝50)≤1.000 (8)

0.001≤Ax650(z＝50)≤0.100 (9)

in the expressions (1) to (9), ax λ and Ax λ (z = 50) are both absorbance at a wavelength λ nm, ax represents absorbance of linearly polarized light oscillating in the x-axis direction, and Ax (z = 50) represents absorbance of linearly polarized light oscillating in the x-axis direction when the optically anisotropic film is rotated by 50 ° about the y-axis as a rotation axis, where the x-axis represents an arbitrary direction in the film surface of the optically anisotropic film, the y-axis represents a direction orthogonal to the x-axis in the film surface, and the z-axis represents a thickness direction of the optically anisotropic film.

2. The optically anisotropic film according to claim 1,

the at least 2 dichroic pigments include a combination of at least 1 cyan pigment and at least 1 magenta pigment, or a combination of at least 1 yellow pigment and at least 1 magenta pigment.

3. The optically anisotropic film according to claim 1, which satisfies any of the following formulae (10) and (11):

0.1≤Ax450(z＝50)/Ax550(z＝50)≤1.5 (10)

0.1≤Ax650(z＝50)/Ax550(z＝50)≤1.5 (11)

in the formulae (10) and (11), ax λ and Ax λ (z = 50) have the same meaning as described above.

4. The optically anisotropic film according to claim 1, having a film thickness of 0.1 μm or more and 5 μm or less,

5. The optically anisotropic film according to claim 4,

the at least 2 dichroic pigments comprise a combination of at least 1 cyan pigment and at least 1 magenta pigment, or a combination of at least 1 yellow pigment and at least 1 magenta pigment,

T×D1＝0.4～1.7 (12)

T×D2＝0.6～2.7 (13)

in the formulae (12) and (13), T represents the film thickness in μm, D1 represents the amount of the cyan dye or the yellow dye with respect to 100 parts by mass of the polymerizable liquid crystal compound, D2 represents the amount of the magenta dye with respect to 100 parts by mass of the polymerizable liquid crystal compound, and the amounts of the cyan dye, the yellow dye, and the magenta dye have units of parts by mass.

6. The optically anisotropic film according to claim 1, comprising at least 1 azo dye as the dichroic dye.

7. The optically anisotropic film according to claim 1,

the polymerizable liquid crystal compound is a liquid crystal compound exhibiting a high-order smectic liquid crystal phase.

8. A laminate comprising the optically anisotropic film of claim 1, a polarizing film, and a horizontally oriented phase difference film.

9. The laminate according to claim 8, which comprises an optically anisotropic film, a polarizing film and a horizontally oriented phase difference film in this order.

10. The laminate according to claim 9, further comprising a vertically-oriented phase difference film on a side of the horizontally-oriented phase difference film opposite to the polarizing film.

11. An organic EL display device comprising the laminate according to claim 8.